1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 
  22 /*
  23  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Portions Copyright 2007 Jeremy Teo
  25  * Portions Copyright 2010 Robert Milkowski
  26  * Copyright (c) 2012, 2017 by Delphix. All rights reserved.
  27  * Copyright (c) 2014 Integros [integros.com]
  28  * Copyright 2015 Joyent, Inc.
  29  * Copyright 2017 Nexenta Systems, Inc.
  30  */
  31 
  32 #include <sys/types.h>
  33 #include <sys/param.h>
  34 #include <sys/time.h>
  35 #include <sys/systm.h>
  36 #include <sys/sysmacros.h>
  37 #include <sys/resource.h>
  38 #include <sys/vfs.h>
  39 #include <sys/vfs_opreg.h>
  40 #include <sys/vnode.h>
  41 #include <sys/file.h>
  42 #include <sys/stat.h>
  43 #include <sys/kmem.h>
  44 #include <sys/taskq.h>
  45 #include <sys/uio.h>
  46 #include <sys/vmsystm.h>
  47 #include <sys/atomic.h>
  48 #include <sys/vm.h>
  49 #include <vm/seg_vn.h>
  50 #include <vm/pvn.h>
  51 #include <vm/as.h>
  52 #include <vm/kpm.h>
  53 #include <vm/seg_kpm.h>
  54 #include <sys/mman.h>
  55 #include <sys/pathname.h>
  56 #include <sys/cmn_err.h>
  57 #include <sys/errno.h>
  58 #include <sys/unistd.h>
  59 #include <sys/zfs_dir.h>
  60 #include <sys/zfs_acl.h>
  61 #include <sys/zfs_ioctl.h>
  62 #include <sys/fs/zfs.h>
  63 #include <sys/dmu.h>
  64 #include <sys/dmu_objset.h>
  65 #include <sys/spa.h>
  66 #include <sys/txg.h>
  67 #include <sys/dbuf.h>
  68 #include <sys/zap.h>
  69 #include <sys/sa.h>
  70 #include <sys/dirent.h>
  71 #include <sys/policy.h>
  72 #include <sys/sunddi.h>
  73 #include <sys/filio.h>
  74 #include <sys/sid.h>
  75 #include "fs/fs_subr.h"
  76 #include <sys/zfs_ctldir.h>
  77 #include <sys/zfs_fuid.h>
  78 #include <sys/zfs_sa.h>
  79 #include <sys/dnlc.h>
  80 #include <sys/zfs_rlock.h>
  81 #include <sys/extdirent.h>
  82 #include <sys/kidmap.h>
  83 #include <sys/cred.h>
  84 #include <sys/attr.h>
  85 #include <sys/dsl_prop.h>
  86 #include <sys/zil.h>
  87 
  88 /*
  89  * Programming rules.
  90  *
  91  * Each vnode op performs some logical unit of work.  To do this, the ZPL must
  92  * properly lock its in-core state, create a DMU transaction, do the work,
  93  * record this work in the intent log (ZIL), commit the DMU transaction,
  94  * and wait for the intent log to commit if it is a synchronous operation.
  95  * Moreover, the vnode ops must work in both normal and log replay context.
  96  * The ordering of events is important to avoid deadlocks and references
  97  * to freed memory.  The example below illustrates the following Big Rules:
  98  *
  99  *  (1) A check must be made in each zfs thread for a mounted file system.
 100  *      This is done avoiding races using ZFS_ENTER(zfsvfs).
 101  *      A ZFS_EXIT(zfsvfs) is needed before all returns.  Any znodes
 102  *      must be checked with ZFS_VERIFY_ZP(zp).  Both of these macros
 103  *      can return EIO from the calling function.
 104  *
 105  *  (2) VN_RELE() should always be the last thing except for zil_commit()
 106  *      (if necessary) and ZFS_EXIT(). This is for 3 reasons:
 107  *      First, if it's the last reference, the vnode/znode
 108  *      can be freed, so the zp may point to freed memory.  Second, the last
 109  *      reference will call zfs_zinactive(), which may induce a lot of work --
 110  *      pushing cached pages (which acquires range locks) and syncing out
 111  *      cached atime changes.  Third, zfs_zinactive() may require a new tx,
 112  *      which could deadlock the system if you were already holding one.
 113  *      If you must call VN_RELE() within a tx then use VN_RELE_ASYNC().
 114  *
 115  *  (3) All range locks must be grabbed before calling dmu_tx_assign(),
 116  *      as they can span dmu_tx_assign() calls.
 117  *
 118  *  (4) If ZPL locks are held, pass TXG_NOWAIT as the second argument to
 119  *      dmu_tx_assign().  This is critical because we don't want to block
 120  *      while holding locks.
 121  *
 122  *      If no ZPL locks are held (aside from ZFS_ENTER()), use TXG_WAIT.  This
 123  *      reduces lock contention and CPU usage when we must wait (note that if
 124  *      throughput is constrained by the storage, nearly every transaction
 125  *      must wait).
 126  *
 127  *      Note, in particular, that if a lock is sometimes acquired before
 128  *      the tx assigns, and sometimes after (e.g. z_lock), then failing
 129  *      to use a non-blocking assign can deadlock the system.  The scenario:
 130  *
 131  *      Thread A has grabbed a lock before calling dmu_tx_assign().
 132  *      Thread B is in an already-assigned tx, and blocks for this lock.
 133  *      Thread A calls dmu_tx_assign(TXG_WAIT) and blocks in txg_wait_open()
 134  *      forever, because the previous txg can't quiesce until B's tx commits.
 135  *
 136  *      If dmu_tx_assign() returns ERESTART and zfsvfs->z_assign is TXG_NOWAIT,
 137  *      then drop all locks, call dmu_tx_wait(), and try again.  On subsequent
 138  *      calls to dmu_tx_assign(), pass TXG_WAITED rather than TXG_NOWAIT,
 139  *      to indicate that this operation has already called dmu_tx_wait().
 140  *      This will ensure that we don't retry forever, waiting a short bit
 141  *      each time.
 142  *
 143  *  (5) If the operation succeeded, generate the intent log entry for it
 144  *      before dropping locks.  This ensures that the ordering of events
 145  *      in the intent log matches the order in which they actually occurred.
 146  *      During ZIL replay the zfs_log_* functions will update the sequence
 147  *      number to indicate the zil transaction has replayed.
 148  *
 149  *  (6) At the end of each vnode op, the DMU tx must always commit,
 150  *      regardless of whether there were any errors.
 151  *
 152  *  (7) After dropping all locks, invoke zil_commit(zilog, foid)
 153  *      to ensure that synchronous semantics are provided when necessary.
 154  *
 155  * In general, this is how things should be ordered in each vnode op:
 156  *
 157  *      ZFS_ENTER(zfsvfs);              // exit if unmounted
 158  * top:
 159  *      zfs_dirent_lock(&dl, ...)   // lock directory entry (may VN_HOLD())
 160  *      rw_enter(...);                  // grab any other locks you need
 161  *      tx = dmu_tx_create(...);        // get DMU tx
 162  *      dmu_tx_hold_*();                // hold each object you might modify
 163  *      error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
 164  *      if (error) {
 165  *              rw_exit(...);           // drop locks
 166  *              zfs_dirent_unlock(dl);  // unlock directory entry
 167  *              VN_RELE(...);           // release held vnodes
 168  *              if (error == ERESTART) {
 169  *                      waited = B_TRUE;
 170  *                      dmu_tx_wait(tx);
 171  *                      dmu_tx_abort(tx);
 172  *                      goto top;
 173  *              }
 174  *              dmu_tx_abort(tx);       // abort DMU tx
 175  *              ZFS_EXIT(zfsvfs);       // finished in zfs
 176  *              return (error);         // really out of space
 177  *      }
 178  *      error = do_real_work();         // do whatever this VOP does
 179  *      if (error == 0)
 180  *              zfs_log_*(...);         // on success, make ZIL entry
 181  *      dmu_tx_commit(tx);              // commit DMU tx -- error or not
 182  *      rw_exit(...);                   // drop locks
 183  *      zfs_dirent_unlock(dl);          // unlock directory entry
 184  *      VN_RELE(...);                   // release held vnodes
 185  *      zil_commit(zilog, foid);        // synchronous when necessary
 186  *      ZFS_EXIT(zfsvfs);               // finished in zfs
 187  *      return (error);                 // done, report error
 188  */
 189 
 190 /* set this tunable to zero to disable asynchronous freeing of files */
 191 boolean_t zfs_do_async_free = B_TRUE;
 192 
 193 /*
 194  * This value will be multiplied by zfs_dirty_data_max to determine
 195  * the threshold past which we will call zfs_inactive_impl() async.
 196  *
 197  * Selecting the multiplier is a balance between how long we're willing to wait
 198  * for delete/free to complete (get shell back, have a NFS thread captive, etc)
 199  * and reducing the number of active requests in the backing taskq.
 200  *
 201  * 4 GiB (zfs_dirty_data_max default) * 16 (multiplier default) = 64 GiB
 202  * meaning by default we will call zfs_inactive_impl async for vnodes > 64 GiB
 203  *
 204  * WARNING: Setting this tunable to zero will enable asynchronous freeing for
 205  * all files which can have undesirable side effects.
 206  */
 207 uint16_t zfs_inactive_async_multiplier = 16;
 208 
 209 int nms_worm_transition_time = 30;
 210 int
 211 zfs_worm_in_trans(znode_t *zp)
 212 {
 213         zfsvfs_t                *zfsvfs = zp->z_zfsvfs;
 214         timestruc_t             now;
 215         sa_bulk_attr_t          bulk[2];
 216         uint64_t                ctime[2];
 217         int                     count = 0;
 218 
 219         if (!nms_worm_transition_time)
 220                 return (0);
 221 
 222         gethrestime(&now);
 223         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
 224             &ctime, sizeof (ctime));
 225         if (sa_bulk_lookup(zp->z_sa_hdl, bulk, count) != 0)
 226                 return (0);
 227 
 228         return ((uint64_t)now.tv_sec - ctime[0] < nms_worm_transition_time);
 229 }
 230 
 231 /* ARGSUSED */
 232 static int
 233 zfs_open(vnode_t **vpp, int flag, cred_t *cr, caller_context_t *ct)
 234 {
 235         znode_t *zp = VTOZ(*vpp);
 236         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
 237 
 238         ZFS_ENTER(zfsvfs);
 239         ZFS_VERIFY_ZP(zp);
 240 
 241         if ((flag & FWRITE) && (zp->z_pflags & ZFS_APPENDONLY) &&
 242             ((flag & FAPPEND) == 0)) {
 243                 ZFS_EXIT(zfsvfs);
 244                 return (SET_ERROR(EPERM));
 245         }
 246 
 247         if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
 248             ZTOV(zp)->v_type == VREG &&
 249             !(zp->z_pflags & ZFS_AV_QUARANTINED) && zp->z_size > 0) {
 250                 if (fs_vscan(*vpp, cr, 0) != 0) {
 251                         ZFS_EXIT(zfsvfs);
 252                         return (SET_ERROR(EACCES));
 253                 }
 254         }
 255 
 256         /* Keep a count of the synchronous opens in the znode */
 257         if (flag & (FSYNC | FDSYNC))
 258                 atomic_inc_32(&zp->z_sync_cnt);
 259 
 260         ZFS_EXIT(zfsvfs);
 261         return (0);
 262 }
 263 
 264 /* ARGSUSED */
 265 static int
 266 zfs_close(vnode_t *vp, int flag, int count, offset_t offset, cred_t *cr,
 267     caller_context_t *ct)
 268 {
 269         znode_t *zp = VTOZ(vp);
 270         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
 271         pid_t caller_pid = (ct != NULL) ? ct->cc_pid : ddi_get_pid();
 272 
 273         /*
 274          * Clean up any locks held by this process on the vp.
 275          */
 276         cleanlocks(vp, caller_pid, 0);
 277         cleanshares(vp, caller_pid);
 278 
 279         ZFS_ENTER(zfsvfs);
 280         ZFS_VERIFY_ZP(zp);
 281 
 282         /* Decrement the synchronous opens in the znode */
 283         if ((flag & (FSYNC | FDSYNC)) && (count == 1))
 284                 atomic_dec_32(&zp->z_sync_cnt);
 285 
 286         if (!zfs_has_ctldir(zp) && zp->z_zfsvfs->z_vscan &&
 287             ZTOV(zp)->v_type == VREG &&
 288             !(zp->z_pflags & ZFS_AV_QUARANTINED) && zp->z_size > 0)
 289                 VERIFY(fs_vscan(vp, cr, 1) == 0);
 290 
 291         ZFS_EXIT(zfsvfs);
 292         return (0);
 293 }
 294 
 295 /*
 296  * Lseek support for finding holes (cmd == _FIO_SEEK_HOLE) and
 297  * data (cmd == _FIO_SEEK_DATA). "off" is an in/out parameter.
 298  */
 299 static int
 300 zfs_holey(vnode_t *vp, int cmd, offset_t *off)
 301 {
 302         znode_t *zp = VTOZ(vp);
 303         uint64_t noff = (uint64_t)*off; /* new offset */
 304         uint64_t file_sz;
 305         int error;
 306         boolean_t hole;
 307 
 308         file_sz = zp->z_size;
 309         if (noff >= file_sz)  {
 310                 return (SET_ERROR(ENXIO));
 311         }
 312 
 313         if (cmd == _FIO_SEEK_HOLE)
 314                 hole = B_TRUE;
 315         else
 316                 hole = B_FALSE;
 317 
 318         error = dmu_offset_next(zp->z_zfsvfs->z_os, zp->z_id, hole, &noff);
 319 
 320         if (error == ESRCH)
 321                 return (SET_ERROR(ENXIO));
 322 
 323         /*
 324          * We could find a hole that begins after the logical end-of-file,
 325          * because dmu_offset_next() only works on whole blocks.  If the
 326          * EOF falls mid-block, then indicate that the "virtual hole"
 327          * at the end of the file begins at the logical EOF, rather than
 328          * at the end of the last block.
 329          */
 330         if (noff > file_sz) {
 331                 ASSERT(hole);
 332                 noff = file_sz;
 333         }
 334 
 335         if (noff < *off)
 336                 return (error);
 337         *off = noff;
 338         return (error);
 339 }
 340 
 341 /* ARGSUSED */
 342 static int
 343 zfs_ioctl(vnode_t *vp, int com, intptr_t data, int flag, cred_t *cred,
 344     int *rvalp, caller_context_t *ct)
 345 {
 346         offset_t off;
 347         offset_t ndata;
 348         dmu_object_info_t doi;
 349         int error;
 350         zfsvfs_t *zfsvfs;
 351         znode_t *zp;
 352 
 353         switch (com) {
 354         case _FIOFFS:
 355         {
 356                 return (zfs_sync(vp->v_vfsp, 0, cred));
 357 
 358                 /*
 359                  * The following two ioctls are used by bfu.  Faking out,
 360                  * necessary to avoid bfu errors.
 361                  */
 362         }
 363         case _FIOGDIO:
 364         case _FIOSDIO:
 365         {
 366                 return (0);
 367         }
 368 
 369         case _FIO_SEEK_DATA:
 370         case _FIO_SEEK_HOLE:
 371         {
 372                 if (ddi_copyin((void *)data, &off, sizeof (off), flag))
 373                         return (SET_ERROR(EFAULT));
 374 
 375                 zp = VTOZ(vp);
 376                 zfsvfs = zp->z_zfsvfs;
 377                 ZFS_ENTER(zfsvfs);
 378                 ZFS_VERIFY_ZP(zp);
 379 
 380                 /* offset parameter is in/out */
 381                 error = zfs_holey(vp, com, &off);
 382                 ZFS_EXIT(zfsvfs);
 383                 if (error)
 384                         return (error);
 385                 if (ddi_copyout(&off, (void *)data, sizeof (off), flag))
 386                         return (SET_ERROR(EFAULT));
 387                 return (0);
 388         }
 389         case _FIO_COUNT_FILLED:
 390         {
 391                 /*
 392                  * _FIO_COUNT_FILLED adds a new ioctl command which
 393                  * exposes the number of filled blocks in a
 394                  * ZFS object.
 395                  */
 396                 zp = VTOZ(vp);
 397                 zfsvfs = zp->z_zfsvfs;
 398                 ZFS_ENTER(zfsvfs);
 399                 ZFS_VERIFY_ZP(zp);
 400 
 401                 /*
 402                  * Wait for all dirty blocks for this object
 403                  * to get synced out to disk, and the DMU info
 404                  * updated.
 405                  */
 406                 error = dmu_object_wait_synced(zfsvfs->z_os, zp->z_id);
 407                 if (error) {
 408                         ZFS_EXIT(zfsvfs);
 409                         return (error);
 410                 }
 411 
 412                 /*
 413                  * Retrieve fill count from DMU object.
 414                  */
 415                 error = dmu_object_info(zfsvfs->z_os, zp->z_id, &doi);
 416                 if (error) {
 417                         ZFS_EXIT(zfsvfs);
 418                         return (error);
 419                 }
 420 
 421                 ndata = doi.doi_fill_count;
 422 
 423                 ZFS_EXIT(zfsvfs);
 424                 if (ddi_copyout(&ndata, (void *)data, sizeof (ndata), flag))
 425                         return (SET_ERROR(EFAULT));
 426                 return (0);
 427         }
 428         }
 429         return (SET_ERROR(ENOTTY));
 430 }
 431 
 432 /*
 433  * Utility functions to map and unmap a single physical page.  These
 434  * are used to manage the mappable copies of ZFS file data, and therefore
 435  * do not update ref/mod bits.
 436  */
 437 caddr_t
 438 zfs_map_page(page_t *pp, enum seg_rw rw)
 439 {
 440         if (kpm_enable)
 441                 return (hat_kpm_mapin(pp, 0));
 442         ASSERT(rw == S_READ || rw == S_WRITE);
 443         return (ppmapin(pp, PROT_READ | ((rw == S_WRITE) ? PROT_WRITE : 0),
 444             (caddr_t)-1));
 445 }
 446 
 447 void
 448 zfs_unmap_page(page_t *pp, caddr_t addr)
 449 {
 450         if (kpm_enable) {
 451                 hat_kpm_mapout(pp, 0, addr);
 452         } else {
 453                 ppmapout(addr);
 454         }
 455 }
 456 
 457 /*
 458  * When a file is memory mapped, we must keep the IO data synchronized
 459  * between the DMU cache and the memory mapped pages.  What this means:
 460  *
 461  * On Write:    If we find a memory mapped page, we write to *both*
 462  *              the page and the dmu buffer.
 463  */
 464 static void
 465 update_pages(vnode_t *vp, int64_t start, int len, objset_t *os, uint64_t oid)
 466 {
 467         int64_t off;
 468 
 469         off = start & PAGEOFFSET;
 470         for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
 471                 page_t *pp;
 472                 uint64_t nbytes = MIN(PAGESIZE - off, len);
 473 
 474                 if (pp = page_lookup(vp, start, SE_SHARED)) {
 475                         caddr_t va;
 476 
 477                         va = zfs_map_page(pp, S_WRITE);
 478                         (void) dmu_read(os, oid, start+off, nbytes, va+off,
 479                             DMU_READ_PREFETCH);
 480                         zfs_unmap_page(pp, va);
 481                         page_unlock(pp);
 482                 }
 483                 len -= nbytes;
 484                 off = 0;
 485         }
 486 }
 487 
 488 /*
 489  * When a file is memory mapped, we must keep the IO data synchronized
 490  * between the DMU cache and the memory mapped pages.  What this means:
 491  *
 492  * On Read:     We "read" preferentially from memory mapped pages,
 493  *              else we default from the dmu buffer.
 494  *
 495  * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when
 496  *       the file is memory mapped.
 497  */
 498 static int
 499 mappedread(vnode_t *vp, int nbytes, uio_t *uio)
 500 {
 501         znode_t *zp = VTOZ(vp);
 502         int64_t start, off;
 503         int len = nbytes;
 504         int error = 0;
 505 
 506         start = uio->uio_loffset;
 507         off = start & PAGEOFFSET;
 508         for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
 509                 page_t *pp;
 510                 uint64_t bytes = MIN(PAGESIZE - off, len);
 511 
 512                 if (pp = page_lookup(vp, start, SE_SHARED)) {
 513                         caddr_t va;
 514 
 515                         va = zfs_map_page(pp, S_READ);
 516                         error = uiomove(va + off, bytes, UIO_READ, uio);
 517                         zfs_unmap_page(pp, va);
 518                         page_unlock(pp);
 519                 } else {
 520                         error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 521                             uio, bytes);
 522                 }
 523                 len -= bytes;
 524                 off = 0;
 525                 if (error)
 526                         break;
 527         }
 528         return (error);
 529 }
 530 
 531 
 532 /*
 533  * ZFS I/O rate throttling
 534  */
 535 
 536 #define DELAY_SHIFT 24
 537 
 538 typedef struct zfs_rate_delay {
 539         uint_t rl_rate;
 540         hrtime_t rl_delay;
 541 } zfs_rate_delay_t;
 542 
 543 /*
 544  * The time we'll attempt to cv_wait (below), in nSec.
 545  * This should be no less than the minimum time it normally takes
 546  * to block a thread and wake back up after the timeout fires.
 547  *
 548  * Each table entry represents the delay for each 4MB of bandwith.
 549  * we reduce the delay as the size fo the I/O increases.
 550  */
 551 zfs_rate_delay_t zfs_rate_delay_table[] = {
 552         {0, 100000},
 553         {1, 100000},
 554         {2, 100000},
 555         {3, 100000},
 556         {4, 100000},
 557         {5, 50000},
 558         {6, 50000},
 559         {7, 50000},
 560         {8, 50000},
 561         {9, 25000},
 562         {10, 25000},
 563         {11, 25000},
 564         {12, 25000},
 565         {13, 12500},
 566         {14, 12500},
 567         {15, 12500},
 568         {16, 12500},
 569         {17, 6250},
 570         {18, 6250},
 571         {19, 6250},
 572         {20, 6250},
 573         {21, 3125},
 574         {22, 3125},
 575         {23, 3125},
 576         {24, 3125},
 577 };
 578 
 579 #define MAX_RATE_TBL_ENTRY 24
 580 
 581 /*
 582  * The delay we use should be reduced based on the size of the iorate
 583  * for higher iorates we want a shorter delay.
 584  */
 585 static inline hrtime_t
 586 zfs_get_delay(ssize_t iorate)
 587 {
 588         uint_t rate = iorate >> DELAY_SHIFT;
 589 
 590         if (rate > MAX_RATE_TBL_ENTRY)
 591                 rate = MAX_RATE_TBL_ENTRY;
 592         return (zfs_rate_delay_table[rate].rl_delay);
 593 }
 594 
 595 /*
 596  * ZFS I/O rate throttling
 597  * See "Token Bucket" on Wikipedia
 598  *
 599  * This is "Token Bucket" with some modifications to avoid wait times
 600  * longer than a couple seconds, so that we don't trigger NFS retries
 601  * or similar.  This does mean that concurrent requests might take us
 602  * over the rate limit, but that's a lesser evil.
 603  */
 604 static void
 605 zfs_rate_throttle(zfsvfs_t *zfsvfs, ssize_t iosize)
 606 {
 607         zfs_rate_state_t *rate = &zfsvfs->z_rate;
 608         hrtime_t now, delta; /* nanoseconds */
 609         int64_t refill;
 610 
 611         VERIFY(rate->rate_cap > 0);
 612         mutex_enter(&rate->rate_lock);
 613 
 614         /*
 615          * If another thread is already waiting, we must queue up behind them.
 616          * We'll wait up to 1 sec here.  We normally will resume by cv_signal,
 617          * so we don't need fine timer resolution on this wait.
 618          */
 619         if (rate->rate_token_bucket < 0) {
 620                 rate->rate_waiters++;
 621                 (void) cv_timedwait_hires(
 622                     &rate->rate_wait_cv, &rate->rate_lock,
 623                     NANOSEC, TR_CLOCK_TICK, 0);
 624                 rate->rate_waiters--;
 625         }
 626 
 627         /*
 628          * How long since we last updated the bucket?
 629          */
 630         now = gethrtime();
 631         delta = now - rate->rate_last_update;
 632         rate->rate_last_update = now;
 633         if (delta < 0)
 634                 delta = 0; /* paranoid */
 635 
 636         /*
 637          * Add "tokens" for time since last update,
 638          * being careful about possible overflow.
 639          */
 640         refill = (delta * rate->rate_cap) / NANOSEC;
 641         if (refill < 0 || refill > rate->rate_cap)
 642                 refill = rate->rate_cap; /* overflow */
 643         rate->rate_token_bucket += refill;
 644         if (rate->rate_token_bucket > rate->rate_cap)
 645                 rate->rate_token_bucket = rate->rate_cap;
 646 
 647         /*
 648          * Withdraw tokens for the current I/O.* If this makes us overdrawn,
 649          * wait an amount of time proportionate to the overdraft.  However,
 650          * as a sanity measure, never wait more than 1 sec, and never try to
 651          * wait less than the time it normally takes to block and reschedule.
 652          *
 653          * Leave the bucket negative while we wait so other threads know to
 654          * queue up. In here, "refill" is the debt we're waiting to pay off.
 655          */
 656         rate->rate_token_bucket -= iosize;
 657         if (rate->rate_token_bucket < 0) {
 658                 hrtime_t zfs_rate_wait = 0;
 659 
 660                 refill = rate->rate_token_bucket;
 661                 DTRACE_PROBE2(zfs_rate_over, zfsvfs_t *, zfsvfs,
 662                     int64_t, refill);
 663 
 664                 if (rate->rate_cap <= 0)
 665                         goto nocap;
 666 
 667                 delta = (refill * NANOSEC) / rate->rate_cap;
 668                 delta = MIN(delta, NANOSEC);
 669 
 670                 zfs_rate_wait = zfs_get_delay(rate->rate_cap);
 671 
 672                 if (delta > zfs_rate_wait) {
 673                         (void) cv_timedwait_hires(
 674                             &rate->rate_wait_cv, &rate->rate_lock,
 675                             delta, TR_CLOCK_TICK, 0);
 676                 }
 677 
 678                 rate->rate_token_bucket += refill;
 679         }
 680 nocap:
 681         if (rate->rate_waiters > 0) {
 682                 cv_signal(&rate->rate_wait_cv);
 683         }
 684 
 685         mutex_exit(&rate->rate_lock);
 686 }
 687 
 688 
 689 offset_t zfs_read_chunk_size = 1024 * 1024; /* Tunable */
 690 
 691 /*
 692  * Read bytes from specified file into supplied buffer.
 693  *
 694  *      IN:     vp      - vnode of file to be read from.
 695  *              uio     - structure supplying read location, range info,
 696  *                        and return buffer.
 697  *              ioflag  - SYNC flags; used to provide FRSYNC semantics.
 698  *              cr      - credentials of caller.
 699  *              ct      - caller context
 700  *
 701  *      OUT:    uio     - updated offset and range, buffer filled.
 702  *
 703  *      RETURN: 0 on success, error code on failure.
 704  *
 705  * Side Effects:
 706  *      vp - atime updated if byte count > 0
 707  */
 708 /* ARGSUSED */
 709 static int
 710 zfs_read(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
 711 {
 712         znode_t         *zp = VTOZ(vp);
 713         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
 714         ssize_t         n, nbytes;
 715         int             error = 0;
 716         rl_t            *rl;
 717         xuio_t          *xuio = NULL;
 718 
 719         ZFS_ENTER(zfsvfs);
 720         ZFS_VERIFY_ZP(zp);
 721 
 722         if (zp->z_pflags & ZFS_AV_QUARANTINED) {
 723                 ZFS_EXIT(zfsvfs);
 724                 return (SET_ERROR(EACCES));
 725         }
 726 
 727         /*
 728          * Validate file offset
 729          */
 730         if (uio->uio_loffset < (offset_t)0) {
 731                 ZFS_EXIT(zfsvfs);
 732                 return (SET_ERROR(EINVAL));
 733         }
 734 
 735         /*
 736          * Fasttrack empty reads
 737          */
 738         if (uio->uio_resid == 0) {
 739                 ZFS_EXIT(zfsvfs);
 740                 return (0);
 741         }
 742 
 743         /*
 744          * Check for mandatory locks
 745          */
 746         if (MANDMODE(zp->z_mode)) {
 747                 if (error = chklock(vp, FREAD,
 748                     uio->uio_loffset, uio->uio_resid, uio->uio_fmode, ct)) {
 749                         ZFS_EXIT(zfsvfs);
 750                         return (error);
 751                 }
 752         }
 753 
 754         /*
 755          * ZFS I/O rate throttling
 756          */
 757         if (zfsvfs->z_rate.rate_cap)
 758                 zfs_rate_throttle(zfsvfs, uio->uio_resid);
 759 
 760         /*
 761          * If we're in FRSYNC mode, sync out this znode before reading it.
 762          */
 763         if (ioflag & FRSYNC || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
 764                 zil_commit(zfsvfs->z_log, zp->z_id);
 765 
 766         /*
 767          * Lock the range against changes.
 768          */
 769         rl = zfs_range_lock(zp, uio->uio_loffset, uio->uio_resid, RL_READER);
 770 
 771         /*
 772          * If we are reading past end-of-file we can skip
 773          * to the end; but we might still need to set atime.
 774          */
 775         if (uio->uio_loffset >= zp->z_size) {
 776                 error = 0;
 777                 goto out;
 778         }
 779 
 780         ASSERT(uio->uio_loffset < zp->z_size);
 781         n = MIN(uio->uio_resid, zp->z_size - uio->uio_loffset);
 782 
 783         if ((uio->uio_extflg == UIO_XUIO) &&
 784             (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY)) {
 785                 int nblk;
 786                 int blksz = zp->z_blksz;
 787                 uint64_t offset = uio->uio_loffset;
 788 
 789                 xuio = (xuio_t *)uio;
 790                 if ((ISP2(blksz))) {
 791                         nblk = (P2ROUNDUP(offset + n, blksz) - P2ALIGN(offset,
 792                             blksz)) / blksz;
 793                 } else {
 794                         ASSERT(offset + n <= blksz);
 795                         nblk = 1;
 796                 }
 797                 (void) dmu_xuio_init(xuio, nblk);
 798 
 799                 if (vn_has_cached_data(vp)) {
 800                         /*
 801                          * For simplicity, we always allocate a full buffer
 802                          * even if we only expect to read a portion of a block.
 803                          */
 804                         while (--nblk >= 0) {
 805                                 (void) dmu_xuio_add(xuio,
 806                                     dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
 807                                     blksz), 0, blksz);
 808                         }
 809                 }
 810         }
 811 
 812         while (n > 0) {
 813                 nbytes = MIN(n, zfs_read_chunk_size -
 814                     P2PHASE(uio->uio_loffset, zfs_read_chunk_size));
 815 
 816                 if (vn_has_cached_data(vp)) {
 817                         error = mappedread(vp, nbytes, uio);
 818                 } else {
 819                         error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
 820                             uio, nbytes);
 821                 }
 822                 if (error) {
 823                         /* convert checksum errors into IO errors */
 824                         if (error == ECKSUM)
 825                                 error = SET_ERROR(EIO);
 826                         break;
 827                 }
 828 
 829                 n -= nbytes;
 830         }
 831 out:
 832         zfs_range_unlock(rl);
 833 
 834         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
 835         ZFS_EXIT(zfsvfs);
 836         return (error);
 837 }
 838 
 839 /*
 840  * Write the bytes to a file.
 841  *
 842  *      IN:     vp      - vnode of file to be written to.
 843  *              uio     - structure supplying write location, range info,
 844  *                        and data buffer.
 845  *              ioflag  - FAPPEND, FSYNC, and/or FDSYNC.  FAPPEND is
 846  *                        set if in append mode.
 847  *              cr      - credentials of caller.
 848  *              ct      - caller context (NFS/CIFS fem monitor only)
 849  *
 850  *      OUT:    uio     - updated offset and range.
 851  *
 852  *      RETURN: 0 on success, error code on failure.
 853  *
 854  * Timestamps:
 855  *      vp - ctime|mtime updated if byte count > 0
 856  */
 857 
 858 /* ARGSUSED */
 859 static int
 860 zfs_write(vnode_t *vp, uio_t *uio, int ioflag, cred_t *cr, caller_context_t *ct)
 861 {
 862         znode_t         *zp = VTOZ(vp);
 863         rlim64_t        limit = uio->uio_llimit;
 864         ssize_t         start_resid = uio->uio_resid;
 865         ssize_t         tx_bytes;
 866         uint64_t        end_size;
 867         dmu_tx_t        *tx;
 868         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
 869         zilog_t         *zilog;
 870         offset_t        woff;
 871         ssize_t         n, nbytes;
 872         rl_t            *rl;
 873         int             max_blksz = zfsvfs->z_max_blksz;
 874         int             error = 0;
 875         arc_buf_t       *abuf;
 876         iovec_t         *aiov = NULL;
 877         xuio_t          *xuio = NULL;
 878         int             i_iov = 0;
 879         int             iovcnt = uio->uio_iovcnt;
 880         iovec_t         *iovp = uio->uio_iov;
 881         int             write_eof;
 882         int             count = 0;
 883         sa_bulk_attr_t  bulk[4];
 884         uint64_t        mtime[2], ctime[2];
 885 
 886         /*
 887          * Fasttrack empty write
 888          */
 889         n = start_resid;
 890         if (n == 0)
 891                 return (0);
 892 
 893         if (limit == RLIM64_INFINITY || limit > MAXOFFSET_T)
 894                 limit = MAXOFFSET_T;
 895 
 896         ZFS_ENTER(zfsvfs);
 897         ZFS_VERIFY_ZP(zp);
 898 
 899         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
 900         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
 901         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
 902             &zp->z_size, 8);
 903         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
 904             &zp->z_pflags, 8);
 905 
 906         /*
 907          * In a case vp->v_vfsp != zp->z_zfsvfs->z_vfs (e.g. snapshots) our
 908          * callers might not be able to detect properly that we are read-only,
 909          * so check it explicitly here.
 910          */
 911         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
 912                 ZFS_EXIT(zfsvfs);
 913                 return (SET_ERROR(EROFS));
 914         }
 915 
 916         /*
 917          * If immutable or not appending then return EPERM.
 918          * Intentionally allow ZFS_READONLY through here.
 919          * See zfs_zaccess_common()
 920          */
 921         if ((zp->z_pflags & ZFS_IMMUTABLE) ||
 922             ((zp->z_pflags & ZFS_APPENDONLY) && !(ioflag & FAPPEND) &&
 923             (uio->uio_loffset < zp->z_size))) {
 924                 /* Make sure we're not a WORM before returning EPERM. */
 925                 if (!(zp->z_pflags & ZFS_IMMUTABLE) ||
 926                     !zp->z_zfsvfs->z_isworm) {
 927                         ZFS_EXIT(zfsvfs);
 928                         return (SET_ERROR(EPERM));
 929                 }
 930         }
 931 
 932         zilog = zfsvfs->z_log;
 933 
 934         /*
 935          * Validate file offset
 936          */
 937         woff = ioflag & FAPPEND ? zp->z_size : uio->uio_loffset;
 938         if (woff < 0) {
 939                 ZFS_EXIT(zfsvfs);
 940                 return (SET_ERROR(EINVAL));
 941         }
 942 
 943         /*
 944          * Check for mandatory locks before calling zfs_range_lock()
 945          * in order to prevent a deadlock with locks set via fcntl().
 946          */
 947         if (MANDMODE((mode_t)zp->z_mode) &&
 948             (error = chklock(vp, FWRITE, woff, n, uio->uio_fmode, ct)) != 0) {
 949                 ZFS_EXIT(zfsvfs);
 950                 return (error);
 951         }
 952 
 953         /*
 954          * ZFS I/O rate throttling
 955          */
 956         if (zfsvfs->z_rate.rate_cap)
 957                 zfs_rate_throttle(zfsvfs, uio->uio_resid);
 958 
 959         /*
 960          * Pre-fault the pages to ensure slow (eg NFS) pages
 961          * don't hold up txg.
 962          * Skip this if uio contains loaned arc_buf.
 963          */
 964         if ((uio->uio_extflg == UIO_XUIO) &&
 965             (((xuio_t *)uio)->xu_type == UIOTYPE_ZEROCOPY))
 966                 xuio = (xuio_t *)uio;
 967         else
 968                 uio_prefaultpages(MIN(n, max_blksz), uio);
 969 
 970         /*
 971          * If in append mode, set the io offset pointer to eof.
 972          */
 973         if (ioflag & FAPPEND) {
 974                 /*
 975                  * Obtain an appending range lock to guarantee file append
 976                  * semantics.  We reset the write offset once we have the lock.
 977                  */
 978                 rl = zfs_range_lock(zp, 0, n, RL_APPEND);
 979                 woff = rl->r_off;
 980                 if (rl->r_len == UINT64_MAX) {
 981                         /*
 982                          * We overlocked the file because this write will cause
 983                          * the file block size to increase.
 984                          * Note that zp_size cannot change with this lock held.
 985                          */
 986                         woff = zp->z_size;
 987                 }
 988                 uio->uio_loffset = woff;
 989         } else {
 990                 /*
 991                  * Note that if the file block size will change as a result of
 992                  * this write, then this range lock will lock the entire file
 993                  * so that we can re-write the block safely.
 994                  */
 995                 rl = zfs_range_lock(zp, woff, n, RL_WRITER);
 996         }
 997 
 998         if (woff >= limit) {
 999                 zfs_range_unlock(rl);
1000                 ZFS_EXIT(zfsvfs);
1001                 return (SET_ERROR(EFBIG));
1002         }
1003 
1004         if ((woff + n) > limit || woff > (limit - n))
1005                 n = limit - woff;
1006 
1007         /* Will this write extend the file length? */
1008         write_eof = (woff + n > zp->z_size);
1009 
1010         end_size = MAX(zp->z_size, woff + n);
1011 
1012         /*
1013          * Write the file in reasonable size chunks.  Each chunk is written
1014          * in a separate transaction; this keeps the intent log records small
1015          * and allows us to do more fine-grained space accounting.
1016          */
1017         while (n > 0) {
1018                 abuf = NULL;
1019                 woff = uio->uio_loffset;
1020                 if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
1021                     zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {
1022                         if (abuf != NULL)
1023                                 dmu_return_arcbuf(abuf);
1024                         error = SET_ERROR(EDQUOT);
1025                         break;
1026                 }
1027 
1028                 if (xuio && abuf == NULL) {
1029                         ASSERT(i_iov < iovcnt);
1030                         aiov = &iovp[i_iov];
1031                         abuf = dmu_xuio_arcbuf(xuio, i_iov);
1032                         dmu_xuio_clear(xuio, i_iov);
1033                         DTRACE_PROBE3(zfs_cp_write, int, i_iov,
1034                             iovec_t *, aiov, arc_buf_t *, abuf);
1035                         ASSERT((aiov->iov_base == abuf->b_data) ||
1036                             ((char *)aiov->iov_base - (char *)abuf->b_data +
1037                             aiov->iov_len == arc_buf_size(abuf)));
1038                         i_iov++;
1039                 } else if (abuf == NULL && n >= max_blksz &&
1040                     woff >= zp->z_size &&
1041                     P2PHASE(woff, max_blksz) == 0 &&
1042                     zp->z_blksz == max_blksz) {
1043                         /*
1044                          * This write covers a full block.  "Borrow" a buffer
1045                          * from the dmu so that we can fill it before we enter
1046                          * a transaction.  This avoids the possibility of
1047                          * holding up the transaction if the data copy hangs
1048                          * up on a pagefault (e.g., from an NFS server mapping).
1049                          */
1050                         size_t cbytes;
1051 
1052                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
1053                             max_blksz);
1054                         ASSERT(abuf != NULL);
1055                         ASSERT(arc_buf_size(abuf) == max_blksz);
1056                         if (error = uiocopy(abuf->b_data, max_blksz,
1057                             UIO_WRITE, uio, &cbytes)) {
1058                                 dmu_return_arcbuf(abuf);
1059                                 break;
1060                         }
1061                         ASSERT(cbytes == max_blksz);
1062                 }
1063 
1064                 /*
1065                  * Start a transaction.
1066                  */
1067                 tx = dmu_tx_create(zfsvfs->z_os);
1068                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
1069                 dmu_tx_hold_write(tx, zp->z_id, woff, MIN(n, max_blksz));
1070                 zfs_sa_upgrade_txholds(tx, zp);
1071                 error = dmu_tx_assign(tx, TXG_WAIT);
1072                 if (error) {
1073                         dmu_tx_abort(tx);
1074                         if (abuf != NULL)
1075                                 dmu_return_arcbuf(abuf);
1076                         break;
1077                 }
1078 
1079                 /*
1080                  * If zfs_range_lock() over-locked we grow the blocksize
1081                  * and then reduce the lock range.  This will only happen
1082                  * on the first iteration since zfs_range_reduce() will
1083                  * shrink down r_len to the appropriate size.
1084                  */
1085                 if (rl->r_len == UINT64_MAX) {
1086                         uint64_t new_blksz;
1087 
1088                         if (zp->z_blksz > max_blksz) {
1089                                 /*
1090                                  * File's blocksize is already larger than the
1091                                  * "recordsize" property.  Only let it grow to
1092                                  * the next power of 2.
1093                                  */
1094                                 ASSERT(!ISP2(zp->z_blksz));
1095                                 new_blksz = MIN(end_size,
1096                                     1 << highbit64(zp->z_blksz));
1097                         } else {
1098                                 new_blksz = MIN(end_size, max_blksz);
1099                         }
1100                         zfs_grow_blocksize(zp, new_blksz, tx);
1101                         zfs_range_reduce(rl, woff, n);
1102                 }
1103 
1104                 /*
1105                  * XXX - should we really limit each write to z_max_blksz?
1106                  * Perhaps we should use SPA_MAXBLOCKSIZE chunks?
1107                  */
1108                 nbytes = MIN(n, max_blksz - P2PHASE(woff, max_blksz));
1109 
1110                 if (abuf == NULL) {
1111                         tx_bytes = uio->uio_resid;
1112                         error = dmu_write_uio_dbuf(sa_get_db(zp->z_sa_hdl),
1113                             uio, nbytes, tx);
1114                         tx_bytes -= uio->uio_resid;
1115                 } else {
1116                         tx_bytes = nbytes;
1117                         ASSERT(xuio == NULL || tx_bytes == aiov->iov_len);
1118                         /*
1119                          * If this is not a full block write, but we are
1120                          * extending the file past EOF and this data starts
1121                          * block-aligned, use assign_arcbuf().  Otherwise,
1122                          * write via dmu_write().
1123                          */
1124                         if (tx_bytes < max_blksz && (!write_eof ||
1125                             aiov->iov_base != abuf->b_data)) {
1126                                 ASSERT(xuio);
1127                                 dmu_write(zfsvfs->z_os, zp->z_id, woff,
1128                                     aiov->iov_len, aiov->iov_base, tx);
1129                                 dmu_return_arcbuf(abuf);
1130                                 xuio_stat_wbuf_copied();
1131                         } else {
1132                                 ASSERT(xuio || tx_bytes == max_blksz);
1133                                 dmu_assign_arcbuf(sa_get_db(zp->z_sa_hdl),
1134                                     woff, abuf, tx);
1135                         }
1136                         ASSERT(tx_bytes <= uio->uio_resid);
1137                         uioskip(uio, tx_bytes);
1138                 }
1139                 if (tx_bytes && vn_has_cached_data(vp)) {
1140                         update_pages(vp, woff,
1141                             tx_bytes, zfsvfs->z_os, zp->z_id);
1142                 }
1143 
1144                 /*
1145                  * If we made no progress, we're done.  If we made even
1146                  * partial progress, update the znode and ZIL accordingly.
1147                  */
1148                 if (tx_bytes == 0) {
1149                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
1150                             (void *)&zp->z_size, sizeof (uint64_t), tx);
1151                         dmu_tx_commit(tx);
1152                         ASSERT(error != 0);
1153                         break;
1154                 }
1155 
1156                 /*
1157                  * Clear Set-UID/Set-GID bits on successful write if not
1158                  * privileged and at least one of the excute bits is set.
1159                  *
1160                  * It would be nice to to this after all writes have
1161                  * been done, but that would still expose the ISUID/ISGID
1162                  * to another app after the partial write is committed.
1163                  *
1164                  * Note: we don't call zfs_fuid_map_id() here because
1165                  * user 0 is not an ephemeral uid.
1166                  */
1167                 mutex_enter(&zp->z_acl_lock);
1168                 if ((zp->z_mode & (S_IXUSR | (S_IXUSR >> 3) |
1169                     (S_IXUSR >> 6))) != 0 &&
1170                     (zp->z_mode & (S_ISUID | S_ISGID)) != 0 &&
1171                     secpolicy_vnode_setid_retain(cr,
1172                     (zp->z_mode & S_ISUID) != 0 && zp->z_uid == 0) != 0) {
1173                         uint64_t newmode;
1174                         zp->z_mode &= ~(S_ISUID | S_ISGID);
1175                         newmode = zp->z_mode;
1176                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_MODE(zfsvfs),
1177                             (void *)&newmode, sizeof (uint64_t), tx);
1178                 }
1179                 mutex_exit(&zp->z_acl_lock);
1180 
1181                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
1182                     B_TRUE);
1183 
1184                 /*
1185                  * Update the file size (zp_size) if it has changed;
1186                  * account for possible concurrent updates.
1187                  */
1188                 while ((end_size = zp->z_size) < uio->uio_loffset) {
1189                         (void) atomic_cas_64(&zp->z_size, end_size,
1190                             uio->uio_loffset);
1191                         ASSERT(error == 0);
1192                 }
1193                 /*
1194                  * If we are replaying and eof is non zero then force
1195                  * the file size to the specified eof. Note, there's no
1196                  * concurrency during replay.
1197                  */
1198                 if (zfsvfs->z_replay && zfsvfs->z_replay_eof != 0)
1199                         zp->z_size = zfsvfs->z_replay_eof;
1200 
1201                 error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
1202 
1203                 zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag);
1204                 dmu_tx_commit(tx);
1205 
1206                 if (error != 0)
1207                         break;
1208                 ASSERT(tx_bytes == nbytes);
1209                 n -= nbytes;
1210 
1211                 if (!xuio && n > 0)
1212                         uio_prefaultpages(MIN(n, max_blksz), uio);
1213         }
1214 
1215         zfs_range_unlock(rl);
1216 
1217         /*
1218          * If we're in replay mode, or we made no progress, return error.
1219          * Otherwise, it's at least a partial write, so it's successful.
1220          */
1221         if (zfsvfs->z_replay || uio->uio_resid == start_resid) {
1222                 ZFS_EXIT(zfsvfs);
1223                 return (error);
1224         }
1225 
1226         if (ioflag & (FSYNC | FDSYNC) ||
1227             zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1228                 zil_commit(zilog, zp->z_id);
1229 
1230         ZFS_EXIT(zfsvfs);
1231         return (0);
1232 }
1233 
1234 /* ARGSUSED */
1235 void
1236 zfs_get_done(zgd_t *zgd, int error)
1237 {
1238         znode_t *zp = zgd->zgd_private;
1239         objset_t *os = zp->z_zfsvfs->z_os;
1240 
1241         if (zgd->zgd_db)
1242                 dmu_buf_rele(zgd->zgd_db, zgd);
1243 
1244         zfs_range_unlock(zgd->zgd_rl);
1245 
1246         /*
1247          * Release the vnode asynchronously as we currently have the
1248          * txg stopped from syncing.
1249          */
1250         VN_RELE_ASYNC(ZTOV(zp), dsl_pool_vnrele_taskq(dmu_objset_pool(os)));
1251 
1252         kmem_free(zgd, sizeof (zgd_t));
1253 }
1254 
1255 #ifdef DEBUG
1256 static int zil_fault_io = 0;
1257 #endif
1258 
1259 /*
1260  * Get data to generate a TX_WRITE intent log record.
1261  */
1262 int
1263 zfs_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, zio_t *zio)
1264 {
1265         zfsvfs_t *zfsvfs = arg;
1266         objset_t *os = zfsvfs->z_os;
1267         znode_t *zp;
1268         uint64_t object = lr->lr_foid;
1269         uint64_t offset = lr->lr_offset;
1270         uint64_t size = lr->lr_length;
1271         dmu_buf_t *db;
1272         zgd_t *zgd;
1273         int error = 0;
1274 
1275         ASSERT3P(lwb, !=, NULL);
1276         ASSERT3P(zio, !=, NULL);
1277         ASSERT3U(size, !=, 0);
1278 
1279         /*
1280          * Nothing to do if the file has been removed
1281          */
1282         if (zfs_zget(zfsvfs, object, &zp) != 0)
1283                 return (SET_ERROR(ENOENT));
1284         if (zp->z_unlinked) {
1285                 /*
1286                  * Release the vnode asynchronously as we currently have the
1287                  * txg stopped from syncing.
1288                  */
1289                 VN_RELE_ASYNC(ZTOV(zp),
1290                     dsl_pool_vnrele_taskq(dmu_objset_pool(os)));
1291                 return (SET_ERROR(ENOENT));
1292         }
1293 
1294         zgd = (zgd_t *)kmem_zalloc(sizeof (zgd_t), KM_SLEEP);
1295         zgd->zgd_lwb = lwb;
1296         zgd->zgd_private = zp;
1297 
1298         /*
1299          * Write records come in two flavors: immediate and indirect.
1300          * For small writes it's cheaper to store the data with the
1301          * log record (immediate); for large writes it's cheaper to
1302          * sync the data and get a pointer to it (indirect) so that
1303          * we don't have to write the data twice.
1304          */
1305         if (buf != NULL) { /* immediate write */
1306                 zgd->zgd_rl = zfs_range_lock(zp, offset, size, RL_READER);
1307                 /* test for truncation needs to be done while range locked */
1308                 if (offset >= zp->z_size) {
1309                         error = SET_ERROR(ENOENT);
1310                 } else {
1311                         error = dmu_read(os, object, offset, size, buf,
1312                             DMU_READ_NO_PREFETCH);
1313                 }
1314                 ASSERT(error == 0 || error == ENOENT);
1315         } else { /* indirect write */
1316                 /*
1317                  * Have to lock the whole block to ensure when it's
1318                  * written out and its checksum is being calculated
1319                  * that no one can change the data. We need to re-check
1320                  * blocksize after we get the lock in case it's changed!
1321                  */
1322                 for (;;) {
1323                         uint64_t blkoff;
1324                         size = zp->z_blksz;
1325                         blkoff = ISP2(size) ? P2PHASE(offset, size) : offset;
1326                         offset -= blkoff;
1327                         zgd->zgd_rl = zfs_range_lock(zp, offset, size,
1328                             RL_READER);
1329                         if (zp->z_blksz == size)
1330                                 break;
1331                         offset += blkoff;
1332                         zfs_range_unlock(zgd->zgd_rl);
1333                 }
1334                 /* test for truncation needs to be done while range locked */
1335                 if (lr->lr_offset >= zp->z_size)
1336                         error = SET_ERROR(ENOENT);
1337 #ifdef DEBUG
1338                 if (zil_fault_io) {
1339                         error = SET_ERROR(EIO);
1340                         zil_fault_io = 0;
1341                 }
1342 #endif
1343                 if (error == 0)
1344                         error = dmu_buf_hold(os, object, offset, zgd, &db,
1345                             DMU_READ_NO_PREFETCH);
1346 
1347                 if (error == 0) {
1348                         blkptr_t *bp = &lr->lr_blkptr;
1349 
1350                         zgd->zgd_db = db;
1351                         zgd->zgd_bp = bp;
1352 
1353                         ASSERT(db->db_offset == offset);
1354                         ASSERT(db->db_size == size);
1355 
1356                         error = dmu_sync(zio, lr->lr_common.lrc_txg,
1357                             zfs_get_done, zgd);
1358                         ASSERT(error || lr->lr_length <= size);
1359 
1360                         /*
1361                          * On success, we need to wait for the write I/O
1362                          * initiated by dmu_sync() to complete before we can
1363                          * release this dbuf.  We will finish everything up
1364                          * in the zfs_get_done() callback.
1365                          */
1366                         if (error == 0)
1367                                 return (0);
1368 
1369                         if (error == EALREADY) {
1370                                 lr->lr_common.lrc_txtype = TX_WRITE2;
1371                                 /*
1372                                  * TX_WRITE2 relies on the data previously
1373                                  * written by the TX_WRITE that caused
1374                                  * EALREADY.  We zero out the BP because
1375                                  * it is the old, currently-on-disk BP.
1376                                  */
1377                                 zgd->zgd_bp = NULL;
1378                                 BP_ZERO(bp);
1379                                 error = 0;
1380                         }
1381                 }
1382         }
1383 
1384         zfs_get_done(zgd, error);
1385 
1386         return (error);
1387 }
1388 
1389 /*ARGSUSED*/
1390 static int
1391 zfs_access(vnode_t *vp, int mode, int flag, cred_t *cr,
1392     caller_context_t *ct)
1393 {
1394         znode_t *zp = VTOZ(vp);
1395         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
1396         int error;
1397 
1398         ZFS_ENTER(zfsvfs);
1399         ZFS_VERIFY_ZP(zp);
1400 
1401         if (flag & V_ACE_MASK)
1402                 error = zfs_zaccess(zp, mode, flag, B_FALSE, cr);
1403         else
1404                 error = zfs_zaccess_rwx(zp, mode, flag, cr);
1405 
1406         ZFS_EXIT(zfsvfs);
1407         return (error);
1408 }
1409 
1410 /*
1411  * If vnode is for a device return a specfs vnode instead.
1412  */
1413 static int
1414 specvp_check(vnode_t **vpp, cred_t *cr)
1415 {
1416         int error = 0;
1417 
1418         if (IS_DEVVP(*vpp)) {
1419                 struct vnode *svp;
1420 
1421                 svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
1422                 VN_RELE(*vpp);
1423                 if (svp == NULL)
1424                         error = SET_ERROR(ENOSYS);
1425                 *vpp = svp;
1426         }
1427         return (error);
1428 }
1429 
1430 
1431 /*
1432  * Lookup an entry in a directory, or an extended attribute directory.
1433  * If it exists, return a held vnode reference for it.
1434  *
1435  *      IN:     dvp     - vnode of directory to search.
1436  *              nm      - name of entry to lookup.
1437  *              pnp     - full pathname to lookup [UNUSED].
1438  *              flags   - LOOKUP_XATTR set if looking for an attribute.
1439  *              rdir    - root directory vnode [UNUSED].
1440  *              cr      - credentials of caller.
1441  *              ct      - caller context
1442  *              direntflags - directory lookup flags
1443  *              realpnp - returned pathname.
1444  *
1445  *      OUT:    vpp     - vnode of located entry, NULL if not found.
1446  *
1447  *      RETURN: 0 on success, error code on failure.
1448  *
1449  * Timestamps:
1450  *      NA
1451  */
1452 /* ARGSUSED */
1453 static int
1454 zfs_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, struct pathname *pnp,
1455     int flags, vnode_t *rdir, cred_t *cr,  caller_context_t *ct,
1456     int *direntflags, pathname_t *realpnp)
1457 {
1458         znode_t *zp, *zdp = VTOZ(dvp);
1459         zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
1460         int     error = 0;
1461 
1462         /*
1463          * Fast path lookup, however we must skip DNLC lookup
1464          * for case folding or normalizing lookups because the
1465          * DNLC code only stores the passed in name.  This means
1466          * creating 'a' and removing 'A' on a case insensitive
1467          * file system would work, but DNLC still thinks 'a'
1468          * exists and won't let you create it again on the next
1469          * pass through fast path.
1470          */
1471         if (!(flags & (LOOKUP_XATTR | FIGNORECASE))) {
1472 
1473                 if (dvp->v_type != VDIR) {
1474                         return (SET_ERROR(ENOTDIR));
1475                 } else if (zdp->z_sa_hdl == NULL) {
1476                         return (SET_ERROR(EIO));
1477                 }
1478 
1479                 if (nm[0] == 0 || (nm[0] == '.' && nm[1] == '\0')) {
1480                         error = zfs_fastaccesschk_execute(zdp, cr);
1481                         if (!error) {
1482                                 *vpp = dvp;
1483                                 VN_HOLD(*vpp);
1484                                 return (0);
1485                         }
1486                         return (error);
1487                 } else if (!zdp->z_zfsvfs->z_norm &&
1488                     (zdp->z_zfsvfs->z_case == ZFS_CASE_SENSITIVE)) {
1489 
1490                         vnode_t *tvp = dnlc_lookup(dvp, nm);
1491 
1492                         if (tvp) {
1493                                 error = zfs_fastaccesschk_execute(zdp, cr);
1494                                 if (error) {
1495                                         VN_RELE(tvp);
1496                                         return (error);
1497                                 }
1498                                 if (tvp == DNLC_NO_VNODE) {
1499                                         VN_RELE(tvp);
1500                                         return (SET_ERROR(ENOENT));
1501                                 } else {
1502                                         *vpp = tvp;
1503                                         return (specvp_check(vpp, cr));
1504                                 }
1505                         }
1506                 }
1507         }
1508 
1509         DTRACE_PROBE2(zfs__fastpath__lookup__miss, vnode_t *, dvp, char *, nm);
1510 
1511         ZFS_ENTER(zfsvfs);
1512         ZFS_VERIFY_ZP(zdp);
1513 
1514         *vpp = NULL;
1515 
1516         if (flags & LOOKUP_XATTR) {
1517                 /*
1518                  * If the xattr property is off, refuse the lookup request.
1519                  */
1520                 if (!(zfsvfs->z_vfs->vfs_flag & VFS_XATTR)) {
1521                         ZFS_EXIT(zfsvfs);
1522                         return (SET_ERROR(EINVAL));
1523                 }
1524 
1525                 /*
1526                  * We don't allow recursive attributes..
1527                  * Maybe someday we will.
1528                  */
1529                 if (zdp->z_pflags & ZFS_XATTR) {
1530                         ZFS_EXIT(zfsvfs);
1531                         return (SET_ERROR(EINVAL));
1532                 }
1533 
1534                 if (error = zfs_get_xattrdir(VTOZ(dvp), vpp, cr, flags)) {
1535                         ZFS_EXIT(zfsvfs);
1536                         return (error);
1537                 }
1538 
1539                 /*
1540                  * Do we have permission to get into attribute directory?
1541                  */
1542 
1543                 if (error = zfs_zaccess(VTOZ(*vpp), ACE_EXECUTE, 0,
1544                     B_FALSE, cr)) {
1545                         VN_RELE(*vpp);
1546                         *vpp = NULL;
1547                 }
1548 
1549                 ZFS_EXIT(zfsvfs);
1550                 return (error);
1551         }
1552 
1553         if (dvp->v_type != VDIR) {
1554                 ZFS_EXIT(zfsvfs);
1555                 return (SET_ERROR(ENOTDIR));
1556         }
1557 
1558         /*
1559          * Check accessibility of directory.
1560          */
1561 
1562         if (error = zfs_zaccess(zdp, ACE_EXECUTE, 0, B_FALSE, cr)) {
1563                 ZFS_EXIT(zfsvfs);
1564                 return (error);
1565         }
1566 
1567         if (zfsvfs->z_utf8 && u8_validate(nm, strlen(nm),
1568             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1569                 ZFS_EXIT(zfsvfs);
1570                 return (SET_ERROR(EILSEQ));
1571         }
1572 
1573         error = zfs_dirlook(zdp, nm, vpp, flags, direntflags, realpnp);
1574         if (error == 0)
1575                 error = specvp_check(vpp, cr);
1576         if (*vpp) {
1577                 zp = VTOZ(*vpp);
1578                 if (!(zp->z_pflags & ZFS_IMMUTABLE) &&
1579                     ((*vpp)->v_type != VDIR) &&
1580                     zfsvfs->z_isworm && !zfs_worm_in_trans(zp)) {
1581                         zp->z_pflags |= ZFS_IMMUTABLE;
1582                 }
1583         }
1584 
1585         ZFS_EXIT(zfsvfs);
1586         return (error);
1587 }
1588 
1589 /*
1590  * Attempt to create a new entry in a directory.  If the entry
1591  * already exists, truncate the file if permissible, else return
1592  * an error.  Return the vp of the created or trunc'd file.
1593  *
1594  *      IN:     dvp     - vnode of directory to put new file entry in.
1595  *              name    - name of new file entry.
1596  *              vap     - attributes of new file.
1597  *              excl    - flag indicating exclusive or non-exclusive mode.
1598  *              mode    - mode to open file with.
1599  *              cr      - credentials of caller.
1600  *              flag    - large file flag [UNUSED].
1601  *              ct      - caller context
1602  *              vsecp   - ACL to be set
1603  *
1604  *      OUT:    vpp     - vnode of created or trunc'd entry.
1605  *
1606  *      RETURN: 0 on success, error code on failure.
1607  *
1608  * Timestamps:
1609  *      dvp - ctime|mtime updated if new entry created
1610  *       vp - ctime|mtime always, atime if new
1611  */
1612 
1613 /* ARGSUSED */
1614 static int
1615 zfs_create(vnode_t *dvp, char *name, vattr_t *vap, vcexcl_t excl,
1616     int mode, vnode_t **vpp, cred_t *cr, int flag, caller_context_t *ct,
1617     vsecattr_t *vsecp)
1618 {
1619         int             imm_was_set = 0;
1620         znode_t         *zp, *dzp = VTOZ(dvp);
1621         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1622         zilog_t         *zilog;
1623         objset_t        *os;
1624         zfs_dirlock_t   *dl;
1625         dmu_tx_t        *tx;
1626         int             error;
1627         ksid_t          *ksid;
1628         uid_t           uid;
1629         gid_t           gid = crgetgid(cr);
1630         zfs_acl_ids_t   acl_ids;
1631         boolean_t       fuid_dirtied;
1632         boolean_t       have_acl = B_FALSE;
1633         boolean_t       waited = B_FALSE;
1634 
1635         /*
1636          * If we have an ephemeral id, ACL, or XVATTR then
1637          * make sure file system is at proper version
1638          */
1639 
1640         ksid = crgetsid(cr, KSID_OWNER);
1641         if (ksid)
1642                 uid = ksid_getid(ksid);
1643         else
1644                 uid = crgetuid(cr);
1645 
1646         if (zfsvfs->z_use_fuids == B_FALSE &&
1647             (vsecp || (vap->va_mask & AT_XVATTR) ||
1648             IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
1649                 return (SET_ERROR(EINVAL));
1650 
1651         ZFS_ENTER(zfsvfs);
1652         ZFS_VERIFY_ZP(dzp);
1653         os = zfsvfs->z_os;
1654         zilog = zfsvfs->z_log;
1655 
1656         if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
1657             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
1658                 ZFS_EXIT(zfsvfs);
1659                 return (SET_ERROR(EILSEQ));
1660         }
1661 
1662         if (vap->va_mask & AT_XVATTR) {
1663                 if ((error = secpolicy_xvattr((xvattr_t *)vap,
1664                     crgetuid(cr), cr, vap->va_type)) != 0) {
1665                         ZFS_EXIT(zfsvfs);
1666                         return (error);
1667                 }
1668         }
1669 top:
1670         *vpp = NULL;
1671 
1672         if ((vap->va_mode & VSVTX) && secpolicy_vnode_stky_modify(cr))
1673                 vap->va_mode &= ~VSVTX;
1674 
1675         if (*name == '\0') {
1676                 /*
1677                  * Null component name refers to the directory itself.
1678                  */
1679                 VN_HOLD(dvp);
1680                 zp = dzp;
1681                 dl = NULL;
1682                 error = 0;
1683         } else {
1684                 /* possible VN_HOLD(zp) */
1685                 int zflg = 0;
1686 
1687                 if (flag & FIGNORECASE)
1688                         zflg |= ZCILOOK;
1689 
1690                 error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1691                     NULL, NULL);
1692                 if (error) {
1693                         if (have_acl)
1694                                 zfs_acl_ids_free(&acl_ids);
1695                         if (strcmp(name, "..") == 0)
1696                                 error = SET_ERROR(EISDIR);
1697                         ZFS_EXIT(zfsvfs);
1698                         return (error);
1699                 }
1700         }
1701 
1702         if (zp == NULL) {
1703                 uint64_t txtype;
1704 
1705                 if ((dzp->z_pflags & ZFS_IMMUTABLE) &&
1706                     dzp->z_zfsvfs->z_isworm) {
1707                         imm_was_set = 1;
1708                         dzp->z_pflags &= ~ZFS_IMMUTABLE;
1709                 }
1710 
1711                 /*
1712                  * Create a new file object and update the directory
1713                  * to reference it.
1714                  */
1715                 if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
1716                         if (have_acl)
1717                                 zfs_acl_ids_free(&acl_ids);
1718                         if (imm_was_set)
1719                                 dzp->z_pflags |= ZFS_IMMUTABLE;
1720                         goto out;
1721                 }
1722 
1723                 if (imm_was_set)
1724                         dzp->z_pflags |= ZFS_IMMUTABLE;
1725 
1726                 /*
1727                  * We only support the creation of regular files in
1728                  * extended attribute directories.
1729                  */
1730 
1731                 if ((dzp->z_pflags & ZFS_XATTR) &&
1732                     (vap->va_type != VREG)) {
1733                         if (have_acl)
1734                                 zfs_acl_ids_free(&acl_ids);
1735                         error = SET_ERROR(EINVAL);
1736                         goto out;
1737                 }
1738 
1739                 if (!have_acl && (error = zfs_acl_ids_create(dzp, 0, vap,
1740                     cr, vsecp, &acl_ids)) != 0)
1741                         goto out;
1742                 have_acl = B_TRUE;
1743 
1744                 if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
1745                         zfs_acl_ids_free(&acl_ids);
1746                         error = SET_ERROR(EDQUOT);
1747                         goto out;
1748                 }
1749 
1750                 tx = dmu_tx_create(os);
1751 
1752                 dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
1753                     ZFS_SA_BASE_ATTR_SIZE);
1754 
1755                 fuid_dirtied = zfsvfs->z_fuid_dirty;
1756                 if (fuid_dirtied)
1757                         zfs_fuid_txhold(zfsvfs, tx);
1758                 dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
1759                 dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
1760                 if (!zfsvfs->z_use_sa &&
1761                     acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
1762                         dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
1763                             0, acl_ids.z_aclp->z_acl_bytes);
1764                 }
1765                 error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
1766                 if (error) {
1767                         zfs_dirent_unlock(dl);
1768                         if (error == ERESTART) {
1769                                 waited = B_TRUE;
1770                                 dmu_tx_wait(tx);
1771                                 dmu_tx_abort(tx);
1772                                 goto top;
1773                         }
1774                         zfs_acl_ids_free(&acl_ids);
1775                         dmu_tx_abort(tx);
1776                         ZFS_EXIT(zfsvfs);
1777                         return (error);
1778                 }
1779                 zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
1780 
1781                 if (fuid_dirtied)
1782                         zfs_fuid_sync(zfsvfs, tx);
1783 
1784                 if (imm_was_set)
1785                         zp->z_pflags |= ZFS_IMMUTABLE;
1786 
1787                 (void) zfs_link_create(dl, zp, tx, ZNEW);
1788                 txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
1789                 if (flag & FIGNORECASE)
1790                         txtype |= TX_CI;
1791                 zfs_log_create(zilog, tx, txtype, dzp, zp, name,
1792                     vsecp, acl_ids.z_fuidp, vap);
1793                 zfs_acl_ids_free(&acl_ids);
1794                 dmu_tx_commit(tx);
1795         } else {
1796                 int aflags = (flag & FAPPEND) ? V_APPEND : 0;
1797 
1798                 if (have_acl)
1799                         zfs_acl_ids_free(&acl_ids);
1800                 have_acl = B_FALSE;
1801 
1802                 /*
1803                  * A directory entry already exists for this name.
1804                  */
1805                 /*
1806                  * Can't truncate an existing file if in exclusive mode.
1807                  */
1808                 if (excl == EXCL) {
1809                         error = SET_ERROR(EEXIST);
1810                         goto out;
1811                 }
1812                 /*
1813                  * Can't open a directory for writing.
1814                  */
1815                 if ((ZTOV(zp)->v_type == VDIR) && (mode & S_IWRITE)) {
1816                         error = SET_ERROR(EISDIR);
1817                         goto out;
1818                 }
1819                 if ((flag & FWRITE) &&
1820                     dzp->z_zfsvfs->z_isworm) {
1821                         error = EPERM;
1822                         goto out;
1823                 }
1824 
1825                 if (!(flag & FAPPEND) &&
1826                     (zp->z_pflags & ZFS_IMMUTABLE) &&
1827                     dzp->z_zfsvfs->z_isworm) {
1828                         imm_was_set = 1;
1829                         zp->z_pflags &= ~ZFS_IMMUTABLE;
1830                 }
1831                 /*
1832                  * Verify requested access to file.
1833                  */
1834                 if (mode && (error = zfs_zaccess_rwx(zp, mode, aflags, cr))) {
1835                         if (imm_was_set)
1836                                 zp->z_pflags |= ZFS_IMMUTABLE;
1837                         goto out;
1838                 }
1839 
1840                 if (imm_was_set)
1841                         zp->z_pflags |= ZFS_IMMUTABLE;
1842 
1843                 mutex_enter(&dzp->z_lock);
1844                 dzp->z_seq++;
1845                 mutex_exit(&dzp->z_lock);
1846 
1847                 /*
1848                  * Truncate regular files if requested.
1849                  */
1850                 if ((ZTOV(zp)->v_type == VREG) &&
1851                     (vap->va_mask & AT_SIZE) && (vap->va_size == 0)) {
1852                         /* we can't hold any locks when calling zfs_freesp() */
1853                         zfs_dirent_unlock(dl);
1854                         dl = NULL;
1855                         error = zfs_freesp(zp, 0, 0, mode, TRUE);
1856                         if (error == 0) {
1857                                 vnevent_create(ZTOV(zp), ct);
1858                         }
1859                 }
1860         }
1861 out:
1862 
1863         if (dl)
1864                 zfs_dirent_unlock(dl);
1865 
1866         if (error) {
1867                 if (zp)
1868                         VN_RELE(ZTOV(zp));
1869         } else {
1870                 *vpp = ZTOV(zp);
1871                 error = specvp_check(vpp, cr);
1872         }
1873 
1874         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
1875                 zil_commit(zilog, 0);
1876 
1877         ZFS_EXIT(zfsvfs);
1878         return (error);
1879 }
1880 
1881 /*
1882  * Remove an entry from a directory.
1883  *
1884  *      IN:     dvp     - vnode of directory to remove entry from.
1885  *              name    - name of entry to remove.
1886  *              cr      - credentials of caller.
1887  *              ct      - caller context
1888  *              flags   - case flags
1889  *
1890  *      RETURN: 0 on success, error code on failure.
1891  *
1892  * Timestamps:
1893  *      dvp - ctime|mtime
1894  *       vp - ctime (if nlink > 0)
1895  */
1896 
1897 uint64_t null_xattr = 0;
1898 
1899 /*ARGSUSED*/
1900 static int
1901 zfs_remove(vnode_t *dvp, char *name, cred_t *cr, caller_context_t *ct,
1902     int flags)
1903 {
1904         znode_t         *zp, *dzp = VTOZ(dvp);
1905         znode_t         *xzp;
1906         vnode_t         *vp;
1907         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
1908         zilog_t         *zilog;
1909         uint64_t        acl_obj, xattr_obj;
1910         uint64_t        xattr_obj_unlinked = 0;
1911         uint64_t        obj = 0;
1912         zfs_dirlock_t   *dl;
1913         dmu_tx_t        *tx;
1914         boolean_t       may_delete_now, delete_now = FALSE;
1915         boolean_t       unlinked, toobig = FALSE;
1916         uint64_t        txtype;
1917         pathname_t      *realnmp = NULL;
1918         pathname_t      realnm;
1919         int             error;
1920         int             zflg = ZEXISTS;
1921         boolean_t       waited = B_FALSE;
1922 
1923         ZFS_ENTER(zfsvfs);
1924         ZFS_VERIFY_ZP(dzp);
1925         zilog = zfsvfs->z_log;
1926 
1927         if (flags & FIGNORECASE) {
1928                 zflg |= ZCILOOK;
1929                 pn_alloc(&realnm);
1930                 realnmp = &realnm;
1931         }
1932 
1933 top:
1934         xattr_obj = 0;
1935         xzp = NULL;
1936         /*
1937          * Attempt to lock directory; fail if entry doesn't exist.
1938          */
1939         if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
1940             NULL, realnmp)) {
1941                 if (realnmp)
1942                         pn_free(realnmp);
1943                 ZFS_EXIT(zfsvfs);
1944                 return (error);
1945         }
1946 
1947         vp = ZTOV(zp);
1948 
1949         if (zp->z_zfsvfs->z_isworm) {
1950                 error = SET_ERROR(EPERM);
1951                 goto out;
1952         }
1953 
1954         if (error = zfs_zaccess_delete(dzp, zp, cr)) {
1955                 goto out;
1956         }
1957 
1958         /*
1959          * Need to use rmdir for removing directories.
1960          */
1961         if (vp->v_type == VDIR) {
1962                 error = SET_ERROR(EPERM);
1963                 goto out;
1964         }
1965 
1966         vnevent_remove(vp, dvp, name, ct);
1967 
1968         if (realnmp)
1969                 dnlc_remove(dvp, realnmp->pn_buf);
1970         else
1971                 dnlc_remove(dvp, name);
1972 
1973         mutex_enter(&vp->v_lock);
1974         may_delete_now = vp->v_count == 1 && !vn_has_cached_data(vp);
1975         mutex_exit(&vp->v_lock);
1976 
1977         /*
1978          * We may delete the znode now, or we may put it in the unlinked set;
1979          * it depends on whether we're the last link, and on whether there are
1980          * other holds on the vnode.  So we dmu_tx_hold() the right things to
1981          * allow for either case.
1982          */
1983         obj = zp->z_id;
1984         tx = dmu_tx_create(zfsvfs->z_os);
1985         dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
1986         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
1987         zfs_sa_upgrade_txholds(tx, zp);
1988         zfs_sa_upgrade_txholds(tx, dzp);
1989         if (may_delete_now) {
1990                 toobig =
1991                     zp->z_size > zp->z_blksz * DMU_MAX_DELETEBLKCNT;
1992                 /* if the file is too big, only hold_free a token amount */
1993                 dmu_tx_hold_free(tx, zp->z_id, 0,
1994                     (toobig ? DMU_MAX_ACCESS : DMU_OBJECT_END));
1995         }
1996 
1997         /* are there any extended attributes? */
1998         error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
1999             &xattr_obj, sizeof (xattr_obj));
2000         if (error == 0 && xattr_obj) {
2001                 error = zfs_zget(zfsvfs, xattr_obj, &xzp);
2002                 ASSERT0(error);
2003                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
2004                 dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
2005         }
2006 
2007         mutex_enter(&zp->z_lock);
2008         if ((acl_obj = zfs_external_acl(zp)) != 0 && may_delete_now)
2009                 dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
2010         mutex_exit(&zp->z_lock);
2011 
2012         /* charge as an update -- would be nice not to charge at all */
2013         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
2014 
2015         /*
2016          * Mark this transaction as typically resulting in a net free of space
2017          */
2018         dmu_tx_mark_netfree(tx);
2019 
2020         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
2021         if (error) {
2022                 zfs_dirent_unlock(dl);
2023                 VN_RELE(vp);
2024                 if (xzp)
2025                         VN_RELE(ZTOV(xzp));
2026                 if (error == ERESTART) {
2027                         waited = B_TRUE;
2028                         dmu_tx_wait(tx);
2029                         dmu_tx_abort(tx);
2030                         goto top;
2031                 }
2032                 if (realnmp)
2033                         pn_free(realnmp);
2034                 dmu_tx_abort(tx);
2035                 ZFS_EXIT(zfsvfs);
2036                 return (error);
2037         }
2038 
2039         /*
2040          * Remove the directory entry.
2041          */
2042         error = zfs_link_destroy(dl, zp, tx, zflg, &unlinked);
2043 
2044         if (error) {
2045                 dmu_tx_commit(tx);
2046                 goto out;
2047         }
2048 
2049         if (unlinked) {
2050                 /*
2051                  * Hold z_lock so that we can make sure that the ACL obj
2052                  * hasn't changed.  Could have been deleted due to
2053                  * zfs_sa_upgrade().
2054                  */
2055                 mutex_enter(&zp->z_lock);
2056                 mutex_enter(&vp->v_lock);
2057                 (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
2058                     &xattr_obj_unlinked, sizeof (xattr_obj_unlinked));
2059                 delete_now = may_delete_now && !toobig &&
2060                     vp->v_count == 1 && !vn_has_cached_data(vp) &&
2061                     xattr_obj == xattr_obj_unlinked && zfs_external_acl(zp) ==
2062                     acl_obj;
2063                 mutex_exit(&vp->v_lock);
2064         }
2065 
2066         if (delete_now) {
2067                 if (xattr_obj_unlinked) {
2068                         ASSERT3U(xzp->z_links, ==, 2);
2069                         mutex_enter(&xzp->z_lock);
2070                         xzp->z_unlinked = 1;
2071                         xzp->z_links = 0;
2072                         error = sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs),
2073                             &xzp->z_links, sizeof (xzp->z_links), tx);
2074                         ASSERT3U(error,  ==,  0);
2075                         mutex_exit(&xzp->z_lock);
2076                         zfs_unlinked_add(xzp, tx);
2077 
2078                         if (zp->z_is_sa)
2079                                 error = sa_remove(zp->z_sa_hdl,
2080                                     SA_ZPL_XATTR(zfsvfs), tx);
2081                         else
2082                                 error = sa_update(zp->z_sa_hdl,
2083                                     SA_ZPL_XATTR(zfsvfs), &null_xattr,
2084                                     sizeof (uint64_t), tx);
2085                         ASSERT0(error);
2086                 }
2087                 mutex_enter(&vp->v_lock);
2088                 VN_RELE_LOCKED(vp);
2089                 ASSERT0(vp->v_count);
2090                 mutex_exit(&vp->v_lock);
2091                 mutex_exit(&zp->z_lock);
2092                 zfs_znode_delete(zp, tx);
2093         } else if (unlinked) {
2094                 mutex_exit(&zp->z_lock);
2095                 zfs_unlinked_add(zp, tx);
2096         }
2097 
2098         txtype = TX_REMOVE;
2099         if (flags & FIGNORECASE)
2100                 txtype |= TX_CI;
2101         zfs_log_remove(zilog, tx, txtype, dzp, name, obj);
2102 
2103         dmu_tx_commit(tx);
2104 out:
2105         if (realnmp)
2106                 pn_free(realnmp);
2107 
2108         zfs_dirent_unlock(dl);
2109 
2110         if (!delete_now)
2111                 VN_RELE(vp);
2112         if (xzp)
2113                 VN_RELE(ZTOV(xzp));
2114 
2115         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
2116                 zil_commit(zilog, 0);
2117 
2118         ZFS_EXIT(zfsvfs);
2119         return (error);
2120 }
2121 
2122 /*
2123  * Create a new directory and insert it into dvp using the name
2124  * provided.  Return a pointer to the inserted directory.
2125  *
2126  *      IN:     dvp     - vnode of directory to add subdir to.
2127  *              dirname - name of new directory.
2128  *              vap     - attributes of new directory.
2129  *              cr      - credentials of caller.
2130  *              ct      - caller context
2131  *              flags   - case flags
2132  *              vsecp   - ACL to be set
2133  *
2134  *      OUT:    vpp     - vnode of created directory.
2135  *
2136  *      RETURN: 0 on success, error code on failure.
2137  *
2138  * Timestamps:
2139  *      dvp - ctime|mtime updated
2140  *       vp - ctime|mtime|atime updated
2141  */
2142 /*ARGSUSED*/
2143 static int
2144 zfs_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, cred_t *cr,
2145     caller_context_t *ct, int flags, vsecattr_t *vsecp)
2146 {
2147         int             imm_was_set = 0;
2148         znode_t         *zp, *dzp = VTOZ(dvp);
2149         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
2150         zilog_t         *zilog;
2151         zfs_dirlock_t   *dl;
2152         uint64_t        txtype;
2153         dmu_tx_t        *tx;
2154         int             error;
2155         int             zf = ZNEW;
2156         ksid_t          *ksid;
2157         uid_t           uid;
2158         gid_t           gid = crgetgid(cr);
2159         zfs_acl_ids_t   acl_ids;
2160         boolean_t       fuid_dirtied;
2161         boolean_t       waited = B_FALSE;
2162 
2163         ASSERT(vap->va_type == VDIR);
2164 
2165         /*
2166          * If we have an ephemeral id, ACL, or XVATTR then
2167          * make sure file system is at proper version
2168          */
2169 
2170         ksid = crgetsid(cr, KSID_OWNER);
2171         if (ksid)
2172                 uid = ksid_getid(ksid);
2173         else
2174                 uid = crgetuid(cr);
2175         if (zfsvfs->z_use_fuids == B_FALSE &&
2176             (vsecp || (vap->va_mask & AT_XVATTR) ||
2177             IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
2178                 return (SET_ERROR(EINVAL));
2179 
2180         ZFS_ENTER(zfsvfs);
2181         ZFS_VERIFY_ZP(dzp);
2182         zilog = zfsvfs->z_log;
2183 
2184         if (dzp->z_pflags & ZFS_XATTR) {
2185                 ZFS_EXIT(zfsvfs);
2186                 return (SET_ERROR(EINVAL));
2187         }
2188 
2189         if (zfsvfs->z_utf8 && u8_validate(dirname,
2190             strlen(dirname), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
2191                 ZFS_EXIT(zfsvfs);
2192                 return (SET_ERROR(EILSEQ));
2193         }
2194         if (flags & FIGNORECASE)
2195                 zf |= ZCILOOK;
2196 
2197         if (vap->va_mask & AT_XVATTR) {
2198                 if ((error = secpolicy_xvattr((xvattr_t *)vap,
2199                     crgetuid(cr), cr, vap->va_type)) != 0) {
2200                         ZFS_EXIT(zfsvfs);
2201                         return (error);
2202                 }
2203         }
2204 
2205         if ((error = zfs_acl_ids_create(dzp, 0, vap, cr,
2206             vsecp, &acl_ids)) != 0) {
2207                 ZFS_EXIT(zfsvfs);
2208                 return (error);
2209         }
2210         /*
2211          * First make sure the new directory doesn't exist.
2212          *
2213          * Existence is checked first to make sure we don't return
2214          * EACCES instead of EEXIST which can cause some applications
2215          * to fail.
2216          */
2217 top:
2218         *vpp = NULL;
2219 
2220         if (error = zfs_dirent_lock(&dl, dzp, dirname, &zp, zf,
2221             NULL, NULL)) {
2222                 zfs_acl_ids_free(&acl_ids);
2223                 ZFS_EXIT(zfsvfs);
2224                 return (error);
2225         }
2226 
2227         if ((dzp->z_pflags & ZFS_IMMUTABLE) &&
2228             dzp->z_zfsvfs->z_isworm) {
2229                 imm_was_set = 1;
2230                 dzp->z_pflags &= ~ZFS_IMMUTABLE;
2231         }
2232 
2233         if (error = zfs_zaccess(dzp, ACE_ADD_SUBDIRECTORY, 0, B_FALSE, cr)) {
2234                 if (imm_was_set)
2235                         dzp->z_pflags |= ZFS_IMMUTABLE;
2236                 zfs_acl_ids_free(&acl_ids);
2237                 zfs_dirent_unlock(dl);
2238                 ZFS_EXIT(zfsvfs);
2239                 return (error);
2240         }
2241 
2242         if (imm_was_set)
2243                 dzp->z_pflags |= ZFS_IMMUTABLE;
2244 
2245         if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
2246                 zfs_acl_ids_free(&acl_ids);
2247                 zfs_dirent_unlock(dl);
2248                 ZFS_EXIT(zfsvfs);
2249                 return (SET_ERROR(EDQUOT));
2250         }
2251 
2252         /*
2253          * Add a new entry to the directory.
2254          */
2255         tx = dmu_tx_create(zfsvfs->z_os);
2256         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, dirname);
2257         dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
2258         fuid_dirtied = zfsvfs->z_fuid_dirty;
2259         if (fuid_dirtied)
2260                 zfs_fuid_txhold(zfsvfs, tx);
2261         if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
2262                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
2263                     acl_ids.z_aclp->z_acl_bytes);
2264         }
2265 
2266         dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
2267             ZFS_SA_BASE_ATTR_SIZE);
2268 
2269         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
2270         if (error) {
2271                 zfs_dirent_unlock(dl);
2272                 if (error == ERESTART) {
2273                         waited = B_TRUE;
2274                         dmu_tx_wait(tx);
2275                         dmu_tx_abort(tx);
2276                         goto top;
2277                 }
2278                 zfs_acl_ids_free(&acl_ids);
2279                 dmu_tx_abort(tx);
2280                 ZFS_EXIT(zfsvfs);
2281                 return (error);
2282         }
2283 
2284         /*
2285          * Create new node.
2286          */
2287         zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
2288 
2289         if (fuid_dirtied)
2290                 zfs_fuid_sync(zfsvfs, tx);
2291 
2292         /*
2293          * Now put new name in parent dir.
2294          */
2295         (void) zfs_link_create(dl, zp, tx, ZNEW);
2296 
2297         *vpp = ZTOV(zp);
2298 
2299         txtype = zfs_log_create_txtype(Z_DIR, vsecp, vap);
2300         if (flags & FIGNORECASE)
2301                 txtype |= TX_CI;
2302         zfs_log_create(zilog, tx, txtype, dzp, zp, dirname, vsecp,
2303             acl_ids.z_fuidp, vap);
2304 
2305         zfs_acl_ids_free(&acl_ids);
2306 
2307         dmu_tx_commit(tx);
2308 
2309         zfs_dirent_unlock(dl);
2310 
2311         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
2312                 zil_commit(zilog, 0);
2313 
2314         ZFS_EXIT(zfsvfs);
2315         return (0);
2316 }
2317 
2318 /*
2319  * Remove a directory subdir entry.  If the current working
2320  * directory is the same as the subdir to be removed, the
2321  * remove will fail.
2322  *
2323  *      IN:     dvp     - vnode of directory to remove from.
2324  *              name    - name of directory to be removed.
2325  *              cwd     - vnode of current working directory.
2326  *              cr      - credentials of caller.
2327  *              ct      - caller context
2328  *              flags   - case flags
2329  *
2330  *      RETURN: 0 on success, error code on failure.
2331  *
2332  * Timestamps:
2333  *      dvp - ctime|mtime updated
2334  */
2335 /*ARGSUSED*/
2336 static int
2337 zfs_rmdir(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
2338     caller_context_t *ct, int flags)
2339 {
2340         znode_t         *dzp = VTOZ(dvp);
2341         znode_t         *zp;
2342         vnode_t         *vp;
2343         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
2344         zilog_t         *zilog;
2345         zfs_dirlock_t   *dl;
2346         dmu_tx_t        *tx;
2347         int             error;
2348         int             zflg = ZEXISTS;
2349         boolean_t       waited = B_FALSE;
2350 
2351         ZFS_ENTER(zfsvfs);
2352         ZFS_VERIFY_ZP(dzp);
2353         zilog = zfsvfs->z_log;
2354 
2355         if (flags & FIGNORECASE)
2356                 zflg |= ZCILOOK;
2357 top:
2358         zp = NULL;
2359 
2360         /*
2361          * Attempt to lock directory; fail if entry doesn't exist.
2362          */
2363         if (error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg,
2364             NULL, NULL)) {
2365                 ZFS_EXIT(zfsvfs);
2366                 return (error);
2367         }
2368 
2369         vp = ZTOV(zp);
2370 
2371         if (dzp->z_zfsvfs->z_isworm) {
2372                 error = SET_ERROR(EPERM);
2373                 goto out;
2374         }
2375 
2376         if (error = zfs_zaccess_delete(dzp, zp, cr)) {
2377                 goto out;
2378         }
2379 
2380         if (vp->v_type != VDIR) {
2381                 error = SET_ERROR(ENOTDIR);
2382                 goto out;
2383         }
2384 
2385         if (vp == cwd) {
2386                 error = SET_ERROR(EINVAL);
2387                 goto out;
2388         }
2389 
2390         vnevent_rmdir(vp, dvp, name, ct);
2391 
2392         /*
2393          * Grab a lock on the directory to make sure that noone is
2394          * trying to add (or lookup) entries while we are removing it.
2395          */
2396         rw_enter(&zp->z_name_lock, RW_WRITER);
2397 
2398         /*
2399          * Grab a lock on the parent pointer to make sure we play well
2400          * with the treewalk and directory rename code.
2401          */
2402         rw_enter(&zp->z_parent_lock, RW_WRITER);
2403 
2404         tx = dmu_tx_create(zfsvfs->z_os);
2405         dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
2406         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
2407         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
2408         zfs_sa_upgrade_txholds(tx, zp);
2409         zfs_sa_upgrade_txholds(tx, dzp);
2410         dmu_tx_mark_netfree(tx);
2411         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
2412         if (error) {
2413                 rw_exit(&zp->z_parent_lock);
2414                 rw_exit(&zp->z_name_lock);
2415                 zfs_dirent_unlock(dl);
2416                 VN_RELE(vp);
2417                 if (error == ERESTART) {
2418                         waited = B_TRUE;
2419                         dmu_tx_wait(tx);
2420                         dmu_tx_abort(tx);
2421                         goto top;
2422                 }
2423                 dmu_tx_abort(tx);
2424                 ZFS_EXIT(zfsvfs);
2425                 return (error);
2426         }
2427 
2428         error = zfs_link_destroy(dl, zp, tx, zflg, NULL);
2429 
2430         if (error == 0) {
2431                 uint64_t txtype = TX_RMDIR;
2432                 if (flags & FIGNORECASE)
2433                         txtype |= TX_CI;
2434                 zfs_log_remove(zilog, tx, txtype, dzp, name, ZFS_NO_OBJECT);
2435         }
2436 
2437         dmu_tx_commit(tx);
2438 
2439         rw_exit(&zp->z_parent_lock);
2440         rw_exit(&zp->z_name_lock);
2441 out:
2442         zfs_dirent_unlock(dl);
2443 
2444         VN_RELE(vp);
2445 
2446         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
2447                 zil_commit(zilog, 0);
2448 
2449         ZFS_EXIT(zfsvfs);
2450         return (error);
2451 }
2452 
2453 /*
2454  * Read as many directory entries as will fit into the provided
2455  * buffer from the given directory cursor position (specified in
2456  * the uio structure).
2457  *
2458  *      IN:     vp      - vnode of directory to read.
2459  *              uio     - structure supplying read location, range info,
2460  *                        and return buffer.
2461  *              cr      - credentials of caller.
2462  *              ct      - caller context
2463  *              flags   - case flags
2464  *
2465  *      OUT:    uio     - updated offset and range, buffer filled.
2466  *              eofp    - set to true if end-of-file detected.
2467  *
2468  *      RETURN: 0 on success, error code on failure.
2469  *
2470  * Timestamps:
2471  *      vp - atime updated
2472  *
2473  * Note that the low 4 bits of the cookie returned by zap is always zero.
2474  * This allows us to use the low range for "special" directory entries:
2475  * We use 0 for '.', and 1 for '..'.  If this is the root of the filesystem,
2476  * we use the offset 2 for the '.zfs' directory.
2477  */
2478 /* ARGSUSED */
2479 static int
2480 zfs_readdir(vnode_t *vp, uio_t *uio, cred_t *cr, int *eofp,
2481     caller_context_t *ct, int flags)
2482 {
2483         znode_t         *zp = VTOZ(vp);
2484         iovec_t         *iovp;
2485         edirent_t       *eodp;
2486         dirent64_t      *odp;
2487         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
2488         objset_t        *os;
2489         caddr_t         outbuf;
2490         size_t          bufsize;
2491         zap_cursor_t    zc;
2492         zap_attribute_t zap;
2493         uint_t          bytes_wanted;
2494         uint64_t        offset; /* must be unsigned; checks for < 1 */
2495         uint64_t        parent;
2496         int             local_eof;
2497         int             outcount;
2498         int             error;
2499         uint8_t         prefetch;
2500         boolean_t       check_sysattrs;
2501 
2502         ZFS_ENTER(zfsvfs);
2503         ZFS_VERIFY_ZP(zp);
2504 
2505         if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
2506             &parent, sizeof (parent))) != 0) {
2507                 ZFS_EXIT(zfsvfs);
2508                 return (error);
2509         }
2510 
2511         /*
2512          * If we are not given an eof variable,
2513          * use a local one.
2514          */
2515         if (eofp == NULL)
2516                 eofp = &local_eof;
2517 
2518         /*
2519          * Check for valid iov_len.
2520          */
2521         if (uio->uio_iov->iov_len <= 0) {
2522                 ZFS_EXIT(zfsvfs);
2523                 return (SET_ERROR(EINVAL));
2524         }
2525 
2526         /*
2527          * Quit if directory has been removed (posix)
2528          */
2529         if ((*eofp = zp->z_unlinked) != 0) {
2530                 ZFS_EXIT(zfsvfs);
2531                 return (0);
2532         }
2533 
2534         error = 0;
2535         os = zfsvfs->z_os;
2536         offset = uio->uio_loffset;
2537         prefetch = zp->z_zn_prefetch;
2538 
2539         /*
2540          * Initialize the iterator cursor.
2541          */
2542         if (offset <= 3) {
2543                 /*
2544                  * Start iteration from the beginning of the directory.
2545                  */
2546                 zap_cursor_init(&zc, os, zp->z_id);
2547         } else {
2548                 /*
2549                  * The offset is a serialized cursor.
2550                  */
2551                 zap_cursor_init_serialized(&zc, os, zp->z_id, offset);
2552         }
2553 
2554         /*
2555          * Get space to change directory entries into fs independent format.
2556          */
2557         iovp = uio->uio_iov;
2558         bytes_wanted = iovp->iov_len;
2559         if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1) {
2560                 bufsize = bytes_wanted;
2561                 outbuf = kmem_alloc(bufsize, KM_SLEEP);
2562                 odp = (struct dirent64 *)outbuf;
2563         } else {
2564                 bufsize = bytes_wanted;
2565                 outbuf = NULL;
2566                 odp = (struct dirent64 *)iovp->iov_base;
2567         }
2568         eodp = (struct edirent *)odp;
2569 
2570         /*
2571          * If this VFS supports the system attribute view interface; and
2572          * we're looking at an extended attribute directory; and we care
2573          * about normalization conflicts on this vfs; then we must check
2574          * for normalization conflicts with the sysattr name space.
2575          */
2576         check_sysattrs = vfs_has_feature(vp->v_vfsp, VFSFT_SYSATTR_VIEWS) &&
2577             (vp->v_flag & V_XATTRDIR) && zfsvfs->z_norm &&
2578             (flags & V_RDDIR_ENTFLAGS);
2579 
2580         /*
2581          * Transform to file-system independent format
2582          */
2583         outcount = 0;
2584         while (outcount < bytes_wanted) {
2585                 ino64_t objnum;
2586                 ushort_t reclen;
2587                 off64_t *next = NULL;
2588 
2589                 /*
2590                  * Special case `.', `..', and `.zfs'.
2591                  */
2592                 if (offset == 0) {
2593                         (void) strcpy(zap.za_name, ".");
2594                         zap.za_normalization_conflict = 0;
2595                         objnum = zp->z_id;
2596                 } else if (offset == 1) {
2597                         (void) strcpy(zap.za_name, "..");
2598                         zap.za_normalization_conflict = 0;
2599                         objnum = parent;
2600                 } else if (offset == 2 && zfs_show_ctldir(zp)) {
2601                         (void) strcpy(zap.za_name, ZFS_CTLDIR_NAME);
2602                         zap.za_normalization_conflict = 0;
2603                         objnum = ZFSCTL_INO_ROOT;
2604                 } else {
2605                         /*
2606                          * Grab next entry.
2607                          */
2608                         if (error = zap_cursor_retrieve(&zc, &zap)) {
2609                                 if ((*eofp = (error == ENOENT)) != 0)
2610                                         break;
2611                                 else
2612                                         goto update;
2613                         }
2614 
2615                         if (zap.za_integer_length != 8 ||
2616                             zap.za_num_integers != 1) {
2617                                 cmn_err(CE_WARN, "zap_readdir: bad directory "
2618                                     "entry, obj = %lld, offset = %lld\n",
2619                                     (u_longlong_t)zp->z_id,
2620                                     (u_longlong_t)offset);
2621                                 error = SET_ERROR(ENXIO);
2622                                 goto update;
2623                         }
2624 
2625                         objnum = ZFS_DIRENT_OBJ(zap.za_first_integer);
2626                         /*
2627                          * MacOS X can extract the object type here such as:
2628                          * uint8_t type = ZFS_DIRENT_TYPE(zap.za_first_integer);
2629                          */
2630 
2631                         if (check_sysattrs && !zap.za_normalization_conflict) {
2632                                 zap.za_normalization_conflict =
2633                                     xattr_sysattr_casechk(zap.za_name);
2634                         }
2635                 }
2636 
2637                 if (flags & V_RDDIR_ACCFILTER) {
2638                         /*
2639                          * If we have no access at all, don't include
2640                          * this entry in the returned information
2641                          */
2642                         znode_t *ezp;
2643                         if (zfs_zget(zp->z_zfsvfs, objnum, &ezp) != 0)
2644                                 goto skip_entry;
2645                         if (!zfs_has_access(ezp, cr)) {
2646                                 VN_RELE(ZTOV(ezp));
2647                                 goto skip_entry;
2648                         }
2649                         VN_RELE(ZTOV(ezp));
2650                 }
2651 
2652                 if (flags & V_RDDIR_ENTFLAGS)
2653                         reclen = EDIRENT_RECLEN(strlen(zap.za_name));
2654                 else
2655                         reclen = DIRENT64_RECLEN(strlen(zap.za_name));
2656 
2657                 /*
2658                  * Will this entry fit in the buffer?
2659                  */
2660                 if (outcount + reclen > bufsize) {
2661                         /*
2662                          * Did we manage to fit anything in the buffer?
2663                          */
2664                         if (!outcount) {
2665                                 error = SET_ERROR(EINVAL);
2666                                 goto update;
2667                         }
2668                         break;
2669                 }
2670                 if (flags & V_RDDIR_ENTFLAGS) {
2671                         /*
2672                          * Add extended flag entry:
2673                          */
2674                         eodp->ed_ino = objnum;
2675                         eodp->ed_reclen = reclen;
2676                         /* NOTE: ed_off is the offset for the *next* entry */
2677                         next = &(eodp->ed_off);
2678                         eodp->ed_eflags = zap.za_normalization_conflict ?
2679                             ED_CASE_CONFLICT : 0;
2680                         (void) strncpy(eodp->ed_name, zap.za_name,
2681                             EDIRENT_NAMELEN(reclen));
2682                         eodp = (edirent_t *)((intptr_t)eodp + reclen);
2683                 } else {
2684                         /*
2685                          * Add normal entry:
2686                          */
2687                         odp->d_ino = objnum;
2688                         odp->d_reclen = reclen;
2689                         /* NOTE: d_off is the offset for the *next* entry */
2690                         next = &(odp->d_off);
2691                         (void) strncpy(odp->d_name, zap.za_name,
2692                             DIRENT64_NAMELEN(reclen));
2693                         odp = (dirent64_t *)((intptr_t)odp + reclen);
2694                 }
2695                 outcount += reclen;
2696 
2697                 ASSERT(outcount <= bufsize);
2698 
2699                 /* Prefetch znode */
2700                 if (prefetch)
2701                         dmu_prefetch(os, objnum, 0, 0, 0,
2702                             ZIO_PRIORITY_SYNC_READ);
2703 
2704         skip_entry:
2705                 /*
2706                  * Move to the next entry, fill in the previous offset.
2707                  */
2708                 if (offset > 2 || (offset == 2 && !zfs_show_ctldir(zp))) {
2709                         zap_cursor_advance(&zc);
2710                         offset = zap_cursor_serialize(&zc);
2711                 } else {
2712                         offset += 1;
2713                 }
2714                 if (next)
2715                         *next = offset;
2716         }
2717         zp->z_zn_prefetch = B_FALSE; /* a lookup will re-enable pre-fetching */
2718 
2719         if (uio->uio_segflg == UIO_SYSSPACE && uio->uio_iovcnt == 1) {
2720                 iovp->iov_base += outcount;
2721                 iovp->iov_len -= outcount;
2722                 uio->uio_resid -= outcount;
2723         } else if (error = uiomove(outbuf, (long)outcount, UIO_READ, uio)) {
2724                 /*
2725                  * Reset the pointer.
2726                  */
2727                 offset = uio->uio_loffset;
2728         }
2729 
2730 update:
2731         zap_cursor_fini(&zc);
2732         if (uio->uio_segflg != UIO_SYSSPACE || uio->uio_iovcnt != 1)
2733                 kmem_free(outbuf, bufsize);
2734 
2735         if (error == ENOENT)
2736                 error = 0;
2737 
2738         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
2739 
2740         uio->uio_loffset = offset;
2741         ZFS_EXIT(zfsvfs);
2742         return (error);
2743 }
2744 
2745 ulong_t zfs_fsync_sync_cnt = 4;
2746 
2747 static int
2748 zfs_fsync(vnode_t *vp, int syncflag, cred_t *cr, caller_context_t *ct)
2749 {
2750         znode_t *zp = VTOZ(vp);
2751         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2752 
2753         /*
2754          * Regardless of whether this is required for standards conformance,
2755          * this is the logical behavior when fsync() is called on a file with
2756          * dirty pages.  We use B_ASYNC since the ZIL transactions are already
2757          * going to be pushed out as part of the zil_commit().
2758          */
2759         if (vn_has_cached_data(vp) && !(syncflag & FNODSYNC) &&
2760             (vp->v_type == VREG) && !(IS_SWAPVP(vp)))
2761                 (void) VOP_PUTPAGE(vp, (offset_t)0, (size_t)0, B_ASYNC, cr, ct);
2762 
2763         (void) tsd_set(zfs_fsyncer_key, (void *)zfs_fsync_sync_cnt);
2764 
2765         if (zfsvfs->z_os->os_sync != ZFS_SYNC_DISABLED) {
2766                 ZFS_ENTER(zfsvfs);
2767                 ZFS_VERIFY_ZP(zp);
2768                 zil_commit(zfsvfs->z_log, zp->z_id);
2769                 ZFS_EXIT(zfsvfs);
2770         }
2771         return (0);
2772 }
2773 
2774 
2775 /*
2776  * Get the requested file attributes and place them in the provided
2777  * vattr structure.
2778  *
2779  *      IN:     vp      - vnode of file.
2780  *              vap     - va_mask identifies requested attributes.
2781  *                        If AT_XVATTR set, then optional attrs are requested
2782  *              flags   - ATTR_NOACLCHECK (CIFS server context)
2783  *              cr      - credentials of caller.
2784  *              ct      - caller context
2785  *
2786  *      OUT:    vap     - attribute values.
2787  *
2788  *      RETURN: 0 (always succeeds).
2789  */
2790 /* ARGSUSED */
2791 static int
2792 zfs_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2793     caller_context_t *ct)
2794 {
2795         znode_t *zp = VTOZ(vp);
2796         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
2797         int     error = 0;
2798         uint64_t links;
2799         uint64_t mtime[2], ctime[2];
2800         xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
2801         xoptattr_t *xoap = NULL;
2802         boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
2803         sa_bulk_attr_t bulk[2];
2804         int count = 0;
2805 
2806         ZFS_ENTER(zfsvfs);
2807         ZFS_VERIFY_ZP(zp);
2808 
2809         zfs_fuid_map_ids(zp, cr, &vap->va_uid, &vap->va_gid);
2810 
2811         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
2812         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
2813 
2814         if ((error = sa_bulk_lookup(zp->z_sa_hdl, bulk, count)) != 0) {
2815                 ZFS_EXIT(zfsvfs);
2816                 return (error);
2817         }
2818 
2819         /*
2820          * If ACL is trivial don't bother looking for ACE_READ_ATTRIBUTES.
2821          * Also, if we are the owner don't bother, since owner should
2822          * always be allowed to read basic attributes of file.
2823          */
2824         if (!(zp->z_pflags & ZFS_ACL_TRIVIAL) &&
2825             (vap->va_uid != crgetuid(cr))) {
2826                 if (error = zfs_zaccess(zp, ACE_READ_ATTRIBUTES, 0,
2827                     skipaclchk, cr)) {
2828                         ZFS_EXIT(zfsvfs);
2829                         return (error);
2830                 }
2831         }
2832 
2833         /*
2834          * Return all attributes.  It's cheaper to provide the answer
2835          * than to determine whether we were asked the question.
2836          */
2837 
2838         mutex_enter(&zp->z_lock);
2839         vap->va_type = vp->v_type;
2840         vap->va_mode = zp->z_mode & MODEMASK;
2841         vap->va_fsid = zp->z_zfsvfs->z_vfs->vfs_dev;
2842         vap->va_nodeid = zp->z_id;
2843         if ((vp->v_flag & VROOT) && zfs_show_ctldir(zp))
2844                 links = zp->z_links + 1;
2845         else
2846                 links = zp->z_links;
2847         vap->va_nlink = MIN(links, UINT32_MAX);      /* nlink_t limit! */
2848         vap->va_size = zp->z_size;
2849         vap->va_rdev = vp->v_rdev;
2850         vap->va_seq = zp->z_seq;
2851 
2852         /*
2853          * Add in any requested optional attributes and the create time.
2854          * Also set the corresponding bits in the returned attribute bitmap.
2855          */
2856         if ((xoap = xva_getxoptattr(xvap)) != NULL && zfsvfs->z_use_fuids) {
2857                 if (XVA_ISSET_REQ(xvap, XAT_ARCHIVE)) {
2858                         xoap->xoa_archive =
2859                             ((zp->z_pflags & ZFS_ARCHIVE) != 0);
2860                         XVA_SET_RTN(xvap, XAT_ARCHIVE);
2861                 }
2862 
2863                 if (XVA_ISSET_REQ(xvap, XAT_READONLY)) {
2864                         xoap->xoa_readonly =
2865                             ((zp->z_pflags & ZFS_READONLY) != 0);
2866                         XVA_SET_RTN(xvap, XAT_READONLY);
2867                 }
2868 
2869                 if (XVA_ISSET_REQ(xvap, XAT_SYSTEM)) {
2870                         xoap->xoa_system =
2871                             ((zp->z_pflags & ZFS_SYSTEM) != 0);
2872                         XVA_SET_RTN(xvap, XAT_SYSTEM);
2873                 }
2874 
2875                 if (XVA_ISSET_REQ(xvap, XAT_HIDDEN)) {
2876                         xoap->xoa_hidden =
2877                             ((zp->z_pflags & ZFS_HIDDEN) != 0);
2878                         XVA_SET_RTN(xvap, XAT_HIDDEN);
2879                 }
2880 
2881                 if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
2882                         xoap->xoa_nounlink =
2883                             ((zp->z_pflags & ZFS_NOUNLINK) != 0);
2884                         XVA_SET_RTN(xvap, XAT_NOUNLINK);
2885                 }
2886 
2887                 if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
2888                         xoap->xoa_immutable =
2889                             ((zp->z_pflags & ZFS_IMMUTABLE) != 0);
2890                         XVA_SET_RTN(xvap, XAT_IMMUTABLE);
2891                 }
2892 
2893                 if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
2894                         xoap->xoa_appendonly =
2895                             ((zp->z_pflags & ZFS_APPENDONLY) != 0);
2896                         XVA_SET_RTN(xvap, XAT_APPENDONLY);
2897                 }
2898 
2899                 if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
2900                         xoap->xoa_nodump =
2901                             ((zp->z_pflags & ZFS_NODUMP) != 0);
2902                         XVA_SET_RTN(xvap, XAT_NODUMP);
2903                 }
2904 
2905                 if (XVA_ISSET_REQ(xvap, XAT_OPAQUE)) {
2906                         xoap->xoa_opaque =
2907                             ((zp->z_pflags & ZFS_OPAQUE) != 0);
2908                         XVA_SET_RTN(xvap, XAT_OPAQUE);
2909                 }
2910 
2911                 if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
2912                         xoap->xoa_av_quarantined =
2913                             ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0);
2914                         XVA_SET_RTN(xvap, XAT_AV_QUARANTINED);
2915                 }
2916 
2917                 if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
2918                         xoap->xoa_av_modified =
2919                             ((zp->z_pflags & ZFS_AV_MODIFIED) != 0);
2920                         XVA_SET_RTN(xvap, XAT_AV_MODIFIED);
2921                 }
2922 
2923                 if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) &&
2924                     vp->v_type == VREG) {
2925                         zfs_sa_get_scanstamp(zp, xvap);
2926                 }
2927 
2928                 if (XVA_ISSET_REQ(xvap, XAT_CREATETIME)) {
2929                         uint64_t times[2];
2930 
2931                         (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs),
2932                             times, sizeof (times));
2933                         ZFS_TIME_DECODE(&xoap->xoa_createtime, times);
2934                         XVA_SET_RTN(xvap, XAT_CREATETIME);
2935                 }
2936 
2937                 if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
2938                         xoap->xoa_reparse = ((zp->z_pflags & ZFS_REPARSE) != 0);
2939                         XVA_SET_RTN(xvap, XAT_REPARSE);
2940                 }
2941                 if (XVA_ISSET_REQ(xvap, XAT_GEN)) {
2942                         xoap->xoa_generation = zp->z_gen;
2943                         XVA_SET_RTN(xvap, XAT_GEN);
2944                 }
2945 
2946                 if (XVA_ISSET_REQ(xvap, XAT_OFFLINE)) {
2947                         xoap->xoa_offline =
2948                             ((zp->z_pflags & ZFS_OFFLINE) != 0);
2949                         XVA_SET_RTN(xvap, XAT_OFFLINE);
2950                 }
2951 
2952                 if (XVA_ISSET_REQ(xvap, XAT_SPARSE)) {
2953                         xoap->xoa_sparse =
2954                             ((zp->z_pflags & ZFS_SPARSE) != 0);
2955                         XVA_SET_RTN(xvap, XAT_SPARSE);
2956                 }
2957         }
2958 
2959         ZFS_TIME_DECODE(&vap->va_atime, zp->z_atime);
2960         ZFS_TIME_DECODE(&vap->va_mtime, mtime);
2961         ZFS_TIME_DECODE(&vap->va_ctime, ctime);
2962 
2963         mutex_exit(&zp->z_lock);
2964 
2965         sa_object_size(zp->z_sa_hdl, &vap->va_blksize, &vap->va_nblocks);
2966 
2967         if (zp->z_blksz == 0) {
2968                 /*
2969                  * Block size hasn't been set; suggest maximal I/O transfers.
2970                  */
2971                 vap->va_blksize = zfsvfs->z_max_blksz;
2972         }
2973 
2974         ZFS_EXIT(zfsvfs);
2975         return (0);
2976 }
2977 
2978 /*
2979  * Set the file attributes to the values contained in the
2980  * vattr structure.
2981  *
2982  *      IN:     vp      - vnode of file to be modified.
2983  *              vap     - new attribute values.
2984  *                        If AT_XVATTR set, then optional attrs are being set
2985  *              flags   - ATTR_UTIME set if non-default time values provided.
2986  *                      - ATTR_NOACLCHECK (CIFS context only).
2987  *              cr      - credentials of caller.
2988  *              ct      - caller context
2989  *
2990  *      RETURN: 0 on success, error code on failure.
2991  *
2992  * Timestamps:
2993  *      vp - ctime updated, mtime updated if size changed.
2994  */
2995 /* ARGSUSED */
2996 static int
2997 zfs_setattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
2998     caller_context_t *ct)
2999 {
3000         znode_t         *zp = VTOZ(vp);
3001         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
3002         zilog_t         *zilog;
3003         dmu_tx_t        *tx;
3004         vattr_t         oldva;
3005         xvattr_t        tmpxvattr;
3006         uint_t          mask = vap->va_mask;
3007         uint_t          saved_mask = 0;
3008         int             trim_mask = 0;
3009         uint64_t        new_mode;
3010         uint64_t        new_uid, new_gid;
3011         uint64_t        xattr_obj;
3012         uint64_t        mtime[2], ctime[2];
3013         znode_t         *attrzp;
3014         int             need_policy = FALSE;
3015         int             err, err2;
3016         zfs_fuid_info_t *fuidp = NULL;
3017         xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
3018         xoptattr_t      *xoap;
3019         zfs_acl_t       *aclp;
3020         boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
3021         boolean_t       fuid_dirtied = B_FALSE;
3022         sa_bulk_attr_t  bulk[7], xattr_bulk[7];
3023         int             count = 0, xattr_count = 0;
3024 
3025         if (mask == 0)
3026                 return (0);
3027 
3028         if (mask & AT_NOSET)
3029                 return (SET_ERROR(EINVAL));
3030 
3031         ZFS_ENTER(zfsvfs);
3032         ZFS_VERIFY_ZP(zp);
3033 
3034         zilog = zfsvfs->z_log;
3035 
3036         /*
3037          * Make sure that if we have ephemeral uid/gid or xvattr specified
3038          * that file system is at proper version level
3039          */
3040 
3041         if (zfsvfs->z_use_fuids == B_FALSE &&
3042             (((mask & AT_UID) && IS_EPHEMERAL(vap->va_uid)) ||
3043             ((mask & AT_GID) && IS_EPHEMERAL(vap->va_gid)) ||
3044             (mask & AT_XVATTR))) {
3045                 ZFS_EXIT(zfsvfs);
3046                 return (SET_ERROR(EINVAL));
3047         }
3048 
3049         if (mask & AT_SIZE && vp->v_type == VDIR) {
3050                 ZFS_EXIT(zfsvfs);
3051                 return (SET_ERROR(EISDIR));
3052         }
3053 
3054         if (mask & AT_SIZE && vp->v_type != VREG && vp->v_type != VFIFO) {
3055                 ZFS_EXIT(zfsvfs);
3056                 return (SET_ERROR(EINVAL));
3057         }
3058 
3059         /*
3060          * If this is an xvattr_t, then get a pointer to the structure of
3061          * optional attributes.  If this is NULL, then we have a vattr_t.
3062          */
3063         xoap = xva_getxoptattr(xvap);
3064 
3065         xva_init(&tmpxvattr);
3066 
3067         /*
3068          * Do not allow to alter immutable bit after it is set
3069          */
3070         if ((zp->z_pflags & ZFS_IMMUTABLE) &&
3071             XVA_ISSET_REQ(xvap, XAT_IMMUTABLE) &&
3072             zp->z_zfsvfs->z_isworm) {
3073                 ZFS_EXIT(zfsvfs);
3074                 return (SET_ERROR(EPERM));
3075         }
3076 
3077         /*
3078          * Immutable files can only alter atime
3079          */
3080         if (((zp->z_pflags & ZFS_IMMUTABLE) || zp->z_zfsvfs->z_isworm) &&
3081             ((mask & (AT_SIZE|AT_UID|AT_GID|AT_MTIME|AT_MODE)) ||
3082             ((mask & AT_XVATTR) && XVA_ISSET_REQ(xvap, XAT_CREATETIME)))) {
3083                 if (!zp->z_zfsvfs->z_isworm || !zfs_worm_in_trans(zp)) {
3084                         ZFS_EXIT(zfsvfs);
3085                         return (SET_ERROR(EPERM));
3086                 }
3087         }
3088 
3089         /*
3090          * Note: ZFS_READONLY is handled in zfs_zaccess_common.
3091          */
3092 
3093         /*
3094          * Verify timestamps doesn't overflow 32 bits.
3095          * ZFS can handle large timestamps, but 32bit syscalls can't
3096          * handle times greater than 2039.  This check should be removed
3097          * once large timestamps are fully supported.
3098          */
3099         if (mask & (AT_ATIME | AT_MTIME)) {
3100                 if (((mask & AT_ATIME) && TIMESPEC_OVERFLOW(&vap->va_atime)) ||
3101                     ((mask & AT_MTIME) && TIMESPEC_OVERFLOW(&vap->va_mtime))) {
3102                         ZFS_EXIT(zfsvfs);
3103                         return (SET_ERROR(EOVERFLOW));
3104                 }
3105         }
3106 
3107 top:
3108         attrzp = NULL;
3109         aclp = NULL;
3110 
3111         /* Can this be moved to before the top label? */
3112         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
3113                 ZFS_EXIT(zfsvfs);
3114                 return (SET_ERROR(EROFS));
3115         }
3116 
3117         /*
3118          * First validate permissions
3119          */
3120 
3121         if (mask & AT_SIZE) {
3122                 err = zfs_zaccess(zp, ACE_WRITE_DATA, 0, skipaclchk, cr);
3123                 if (err) {
3124                         ZFS_EXIT(zfsvfs);
3125                         return (err);
3126                 }
3127                 /*
3128                  * XXX - Note, we are not providing any open
3129                  * mode flags here (like FNDELAY), so we may
3130                  * block if there are locks present... this
3131                  * should be addressed in openat().
3132                  */
3133                 /* XXX - would it be OK to generate a log record here? */
3134                 err = zfs_freesp(zp, vap->va_size, 0, 0, FALSE);
3135                 if (err) {
3136                         ZFS_EXIT(zfsvfs);
3137                         return (err);
3138                 }
3139 
3140                 if (vap->va_size == 0)
3141                         vnevent_truncate(ZTOV(zp), ct);
3142         }
3143 
3144         if (mask & (AT_ATIME|AT_MTIME) ||
3145             ((mask & AT_XVATTR) && (XVA_ISSET_REQ(xvap, XAT_HIDDEN) ||
3146             XVA_ISSET_REQ(xvap, XAT_READONLY) ||
3147             XVA_ISSET_REQ(xvap, XAT_ARCHIVE) ||
3148             XVA_ISSET_REQ(xvap, XAT_OFFLINE) ||
3149             XVA_ISSET_REQ(xvap, XAT_SPARSE) ||
3150             XVA_ISSET_REQ(xvap, XAT_CREATETIME) ||
3151             XVA_ISSET_REQ(xvap, XAT_SYSTEM)))) {
3152                 need_policy = zfs_zaccess(zp, ACE_WRITE_ATTRIBUTES, 0,
3153                     skipaclchk, cr);
3154         }
3155 
3156         if (mask & (AT_UID|AT_GID)) {
3157                 int     idmask = (mask & (AT_UID|AT_GID));
3158                 int     take_owner;
3159                 int     take_group;
3160 
3161                 /*
3162                  * NOTE: even if a new mode is being set,
3163                  * we may clear S_ISUID/S_ISGID bits.
3164                  */
3165 
3166                 if (!(mask & AT_MODE))
3167                         vap->va_mode = zp->z_mode;
3168 
3169                 /*
3170                  * Take ownership or chgrp to group we are a member of
3171                  */
3172 
3173                 take_owner = (mask & AT_UID) && (vap->va_uid == crgetuid(cr));
3174                 take_group = (mask & AT_GID) &&
3175                     zfs_groupmember(zfsvfs, vap->va_gid, cr);
3176 
3177                 /*
3178                  * If both AT_UID and AT_GID are set then take_owner and
3179                  * take_group must both be set in order to allow taking
3180                  * ownership.
3181                  *
3182                  * Otherwise, send the check through secpolicy_vnode_setattr()
3183                  *
3184                  */
3185 
3186                 if (((idmask == (AT_UID|AT_GID)) && take_owner && take_group) ||
3187                     ((idmask == AT_UID) && take_owner) ||
3188                     ((idmask == AT_GID) && take_group)) {
3189                         if (zfs_zaccess(zp, ACE_WRITE_OWNER, 0,
3190                             skipaclchk, cr) == 0) {
3191                                 /*
3192                                  * Remove setuid/setgid for non-privileged users
3193                                  */
3194                                 secpolicy_setid_clear(vap, cr);
3195                                 trim_mask = (mask & (AT_UID|AT_GID));
3196                         } else {
3197                                 need_policy =  TRUE;
3198                         }
3199                 } else {
3200                         need_policy =  TRUE;
3201                 }
3202         }
3203 
3204         mutex_enter(&zp->z_lock);
3205         oldva.va_mode = zp->z_mode;
3206         zfs_fuid_map_ids(zp, cr, &oldva.va_uid, &oldva.va_gid);
3207         if (mask & AT_XVATTR) {
3208                 /*
3209                  * Update xvattr mask to include only those attributes
3210                  * that are actually changing.
3211                  *
3212                  * the bits will be restored prior to actually setting
3213                  * the attributes so the caller thinks they were set.
3214                  */
3215                 if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
3216                         if (xoap->xoa_appendonly !=
3217                             ((zp->z_pflags & ZFS_APPENDONLY) != 0)) {
3218                                 need_policy = TRUE;
3219                         } else {
3220                                 XVA_CLR_REQ(xvap, XAT_APPENDONLY);
3221                                 XVA_SET_REQ(&tmpxvattr, XAT_APPENDONLY);
3222                         }
3223                 }
3224 
3225                 if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
3226                         if (xoap->xoa_nounlink !=
3227                             ((zp->z_pflags & ZFS_NOUNLINK) != 0)) {
3228                                 need_policy = TRUE;
3229                         } else {
3230                                 XVA_CLR_REQ(xvap, XAT_NOUNLINK);
3231                                 XVA_SET_REQ(&tmpxvattr, XAT_NOUNLINK);
3232                         }
3233                 }
3234 
3235                 if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
3236                         if (xoap->xoa_immutable !=
3237                             ((zp->z_pflags & ZFS_IMMUTABLE) != 0)) {
3238                                 need_policy = TRUE;
3239                         } else {
3240                                 XVA_CLR_REQ(xvap, XAT_IMMUTABLE);
3241                                 XVA_SET_REQ(&tmpxvattr, XAT_IMMUTABLE);
3242                         }
3243                 }
3244 
3245                 if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
3246                         if (xoap->xoa_nodump !=
3247                             ((zp->z_pflags & ZFS_NODUMP) != 0)) {
3248                                 need_policy = TRUE;
3249                         } else {
3250                                 XVA_CLR_REQ(xvap, XAT_NODUMP);
3251                                 XVA_SET_REQ(&tmpxvattr, XAT_NODUMP);
3252                         }
3253                 }
3254 
3255                 if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
3256                         if (xoap->xoa_av_modified !=
3257                             ((zp->z_pflags & ZFS_AV_MODIFIED) != 0)) {
3258                                 need_policy = TRUE;
3259                         } else {
3260                                 XVA_CLR_REQ(xvap, XAT_AV_MODIFIED);
3261                                 XVA_SET_REQ(&tmpxvattr, XAT_AV_MODIFIED);
3262                         }
3263                 }
3264 
3265                 if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
3266                         if ((vp->v_type != VREG &&
3267                             xoap->xoa_av_quarantined) ||
3268                             xoap->xoa_av_quarantined !=
3269                             ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0)) {
3270                                 need_policy = TRUE;
3271                         } else {
3272                                 XVA_CLR_REQ(xvap, XAT_AV_QUARANTINED);
3273                                 XVA_SET_REQ(&tmpxvattr, XAT_AV_QUARANTINED);
3274                         }
3275                 }
3276 
3277                 if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
3278                         mutex_exit(&zp->z_lock);
3279                         ZFS_EXIT(zfsvfs);
3280                         return (SET_ERROR(EPERM));
3281                 }
3282 
3283                 if (need_policy == FALSE &&
3284                     (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) ||
3285                     XVA_ISSET_REQ(xvap, XAT_OPAQUE))) {
3286                         need_policy = TRUE;
3287                 }
3288         }
3289 
3290         mutex_exit(&zp->z_lock);
3291 
3292         if (mask & AT_MODE) {
3293                 if (zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr) == 0) {
3294                         err = secpolicy_setid_setsticky_clear(vp, vap,
3295                             &oldva, cr);
3296                         if (err) {
3297                                 ZFS_EXIT(zfsvfs);
3298                                 return (err);
3299                         }
3300                         trim_mask |= AT_MODE;
3301                 } else {
3302                         need_policy = TRUE;
3303                 }
3304         }
3305 
3306         if (need_policy) {
3307                 /*
3308                  * If trim_mask is set then take ownership
3309                  * has been granted or write_acl is present and user
3310                  * has the ability to modify mode.  In that case remove
3311                  * UID|GID and or MODE from mask so that
3312                  * secpolicy_vnode_setattr() doesn't revoke it.
3313                  */
3314 
3315                 if (trim_mask) {
3316                         saved_mask = vap->va_mask;
3317                         vap->va_mask &= ~trim_mask;
3318                 }
3319                 err = secpolicy_vnode_setattr(cr, vp, vap, &oldva, flags,
3320                     (int (*)(void *, int, cred_t *))zfs_zaccess_unix, zp);
3321                 if (err) {
3322                         ZFS_EXIT(zfsvfs);
3323                         return (err);
3324                 }
3325 
3326                 if (trim_mask)
3327                         vap->va_mask |= saved_mask;
3328         }
3329 
3330         /*
3331          * secpolicy_vnode_setattr, or take ownership may have
3332          * changed va_mask
3333          */
3334         mask = vap->va_mask;
3335 
3336         if ((mask & (AT_UID | AT_GID))) {
3337                 err = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
3338                     &xattr_obj, sizeof (xattr_obj));
3339 
3340                 if (err == 0 && xattr_obj) {
3341                         err = zfs_zget(zp->z_zfsvfs, xattr_obj, &attrzp);
3342                         if (err)
3343                                 goto out2;
3344                 }
3345                 if (mask & AT_UID) {
3346                         new_uid = zfs_fuid_create(zfsvfs,
3347                             (uint64_t)vap->va_uid, cr, ZFS_OWNER, &fuidp);
3348                         if (new_uid != zp->z_uid &&
3349                             zfs_fuid_overquota(zfsvfs, B_FALSE, new_uid)) {
3350                                 if (attrzp)
3351                                         VN_RELE(ZTOV(attrzp));
3352                                 err = SET_ERROR(EDQUOT);
3353                                 goto out2;
3354                         }
3355                 }
3356 
3357                 if (mask & AT_GID) {
3358                         new_gid = zfs_fuid_create(zfsvfs, (uint64_t)vap->va_gid,
3359                             cr, ZFS_GROUP, &fuidp);
3360                         if (new_gid != zp->z_gid &&
3361                             zfs_fuid_overquota(zfsvfs, B_TRUE, new_gid)) {
3362                                 if (attrzp)
3363                                         VN_RELE(ZTOV(attrzp));
3364                                 err = SET_ERROR(EDQUOT);
3365                                 goto out2;
3366                         }
3367                 }
3368         }
3369         tx = dmu_tx_create(zfsvfs->z_os);
3370 
3371         if (mask & AT_MODE) {
3372                 uint64_t pmode = zp->z_mode;
3373                 uint64_t acl_obj;
3374                 new_mode = (pmode & S_IFMT) | (vap->va_mode & ~S_IFMT);
3375 
3376                 if (zp->z_zfsvfs->z_acl_mode == ZFS_ACL_RESTRICTED &&
3377                     !(zp->z_pflags & ZFS_ACL_TRIVIAL)) {
3378                         err = SET_ERROR(EPERM);
3379                         goto out;
3380                 }
3381 
3382                 if (err = zfs_acl_chmod_setattr(zp, &aclp, new_mode))
3383                         goto out;
3384 
3385                 mutex_enter(&zp->z_lock);
3386                 if (!zp->z_is_sa && ((acl_obj = zfs_external_acl(zp)) != 0)) {
3387                         /*
3388                          * Are we upgrading ACL from old V0 format
3389                          * to V1 format?
3390                          */
3391                         if (zfsvfs->z_version >= ZPL_VERSION_FUID &&
3392                             zfs_znode_acl_version(zp) ==
3393                             ZFS_ACL_VERSION_INITIAL) {
3394                                 dmu_tx_hold_free(tx, acl_obj, 0,
3395                                     DMU_OBJECT_END);
3396                                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
3397                                     0, aclp->z_acl_bytes);
3398                         } else {
3399                                 dmu_tx_hold_write(tx, acl_obj, 0,
3400                                     aclp->z_acl_bytes);
3401                         }
3402                 } else if (!zp->z_is_sa && aclp->z_acl_bytes > ZFS_ACE_SPACE) {
3403                         dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
3404                             0, aclp->z_acl_bytes);
3405                 }
3406                 mutex_exit(&zp->z_lock);
3407                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
3408         } else {
3409                 if ((mask & AT_XVATTR) &&
3410                     XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP))
3411                         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
3412                 else
3413                         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
3414         }
3415 
3416         if (attrzp) {
3417                 dmu_tx_hold_sa(tx, attrzp->z_sa_hdl, B_FALSE);
3418         }
3419 
3420         fuid_dirtied = zfsvfs->z_fuid_dirty;
3421         if (fuid_dirtied)
3422                 zfs_fuid_txhold(zfsvfs, tx);
3423 
3424         zfs_sa_upgrade_txholds(tx, zp);
3425 
3426         err = dmu_tx_assign(tx, TXG_WAIT);
3427         if (err)
3428                 goto out;
3429 
3430         count = 0;
3431         /*
3432          * Set each attribute requested.
3433          * We group settings according to the locks they need to acquire.
3434          *
3435          * Note: you cannot set ctime directly, although it will be
3436          * updated as a side-effect of calling this function.
3437          */
3438 
3439 
3440         if (mask & (AT_UID|AT_GID|AT_MODE))
3441                 mutex_enter(&zp->z_acl_lock);
3442         mutex_enter(&zp->z_lock);
3443 
3444         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
3445             &zp->z_pflags, sizeof (zp->z_pflags));
3446 
3447         if (attrzp) {
3448                 if (mask & (AT_UID|AT_GID|AT_MODE))
3449                         mutex_enter(&attrzp->z_acl_lock);
3450                 mutex_enter(&attrzp->z_lock);
3451                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3452                     SA_ZPL_FLAGS(zfsvfs), NULL, &attrzp->z_pflags,
3453                     sizeof (attrzp->z_pflags));
3454         }
3455 
3456         if (mask & (AT_UID|AT_GID)) {
3457 
3458                 if (mask & AT_UID) {
3459                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_UID(zfsvfs), NULL,
3460                             &new_uid, sizeof (new_uid));
3461                         zp->z_uid = new_uid;
3462                         if (attrzp) {
3463                                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3464                                     SA_ZPL_UID(zfsvfs), NULL, &new_uid,
3465                                     sizeof (new_uid));
3466                                 attrzp->z_uid = new_uid;
3467                         }
3468                 }
3469 
3470                 if (mask & AT_GID) {
3471                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GID(zfsvfs),
3472                             NULL, &new_gid, sizeof (new_gid));
3473                         zp->z_gid = new_gid;
3474                         if (attrzp) {
3475                                 SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3476                                     SA_ZPL_GID(zfsvfs), NULL, &new_gid,
3477                                     sizeof (new_gid));
3478                                 attrzp->z_gid = new_gid;
3479                         }
3480                 }
3481                 if (!(mask & AT_MODE)) {
3482                         SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs),
3483                             NULL, &new_mode, sizeof (new_mode));
3484                         new_mode = zp->z_mode;
3485                 }
3486                 err = zfs_acl_chown_setattr(zp);
3487                 ASSERT(err == 0);
3488                 if (attrzp) {
3489                         err = zfs_acl_chown_setattr(attrzp);
3490                         ASSERT(err == 0);
3491                 }
3492         }
3493 
3494         if (mask & AT_MODE) {
3495                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs), NULL,
3496                     &new_mode, sizeof (new_mode));
3497                 zp->z_mode = new_mode;
3498                 ASSERT3U((uintptr_t)aclp, !=, NULL);
3499                 err = zfs_aclset_common(zp, aclp, cr, tx);
3500                 ASSERT0(err);
3501                 if (zp->z_acl_cached)
3502                         zfs_acl_free(zp->z_acl_cached);
3503                 zp->z_acl_cached = aclp;
3504                 aclp = NULL;
3505         }
3506 
3507 
3508         if (mask & AT_ATIME) {
3509                 ZFS_TIME_ENCODE(&vap->va_atime, zp->z_atime);
3510                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_ATIME(zfsvfs), NULL,
3511                     &zp->z_atime, sizeof (zp->z_atime));
3512         }
3513 
3514         if (mask & AT_MTIME) {
3515                 ZFS_TIME_ENCODE(&vap->va_mtime, mtime);
3516                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
3517                     mtime, sizeof (mtime));
3518         }
3519 
3520         /* XXX - shouldn't this be done *before* the ATIME/MTIME checks? */
3521         if (mask & AT_SIZE && !(mask & AT_MTIME)) {
3522                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
3523                     NULL, mtime, sizeof (mtime));
3524                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
3525                     &ctime, sizeof (ctime));
3526                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
3527                     B_TRUE);
3528         } else if (mask != 0) {
3529                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
3530                     &ctime, sizeof (ctime));
3531                 zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
3532                     B_TRUE);
3533                 if (attrzp) {
3534                         SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
3535                             SA_ZPL_CTIME(zfsvfs), NULL,
3536                             &ctime, sizeof (ctime));
3537                         zfs_tstamp_update_setup(attrzp, STATE_CHANGED,
3538                             mtime, ctime, B_TRUE);
3539                 }
3540         }
3541         /*
3542          * Do this after setting timestamps to prevent timestamp
3543          * update from toggling bit
3544          */
3545 
3546         if (xoap && (mask & AT_XVATTR)) {
3547 
3548                 /*
3549                  * restore trimmed off masks
3550                  * so that return masks can be set for caller.
3551                  */
3552 
3553                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_APPENDONLY)) {
3554                         XVA_SET_REQ(xvap, XAT_APPENDONLY);
3555                 }
3556                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_NOUNLINK)) {
3557                         XVA_SET_REQ(xvap, XAT_NOUNLINK);
3558                 }
3559                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_IMMUTABLE)) {
3560                         XVA_SET_REQ(xvap, XAT_IMMUTABLE);
3561                 }
3562                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_NODUMP)) {
3563                         XVA_SET_REQ(xvap, XAT_NODUMP);
3564                 }
3565                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_MODIFIED)) {
3566                         XVA_SET_REQ(xvap, XAT_AV_MODIFIED);
3567                 }
3568                 if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_QUARANTINED)) {
3569                         XVA_SET_REQ(xvap, XAT_AV_QUARANTINED);
3570                 }
3571 
3572                 if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP))
3573                         ASSERT(vp->v_type == VREG);
3574 
3575                 zfs_xvattr_set(zp, xvap, tx);
3576         }
3577 
3578         if (fuid_dirtied)
3579                 zfs_fuid_sync(zfsvfs, tx);
3580 
3581         if (mask != 0)
3582                 zfs_log_setattr(zilog, tx, TX_SETATTR, zp, vap, mask, fuidp);
3583 
3584         mutex_exit(&zp->z_lock);
3585         if (mask & (AT_UID|AT_GID|AT_MODE))
3586                 mutex_exit(&zp->z_acl_lock);
3587 
3588         if (attrzp) {
3589                 if (mask & (AT_UID|AT_GID|AT_MODE))
3590                         mutex_exit(&attrzp->z_acl_lock);
3591                 mutex_exit(&attrzp->z_lock);
3592         }
3593 out:
3594         if (err == 0 && attrzp) {
3595                 err2 = sa_bulk_update(attrzp->z_sa_hdl, xattr_bulk,
3596                     xattr_count, tx);
3597                 ASSERT(err2 == 0);
3598         }
3599 
3600         if (attrzp)
3601                 VN_RELE(ZTOV(attrzp));
3602 
3603         if (aclp)
3604                 zfs_acl_free(aclp);
3605 
3606         if (fuidp) {
3607                 zfs_fuid_info_free(fuidp);
3608                 fuidp = NULL;
3609         }
3610 
3611         if (err) {
3612                 dmu_tx_abort(tx);
3613                 if (err == ERESTART)
3614                         goto top;
3615         } else {
3616                 err2 = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
3617                 dmu_tx_commit(tx);
3618         }
3619 
3620 out2:
3621         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
3622                 zil_commit(zilog, 0);
3623 
3624         ZFS_EXIT(zfsvfs);
3625         return (err);
3626 }
3627 
3628 typedef struct zfs_zlock {
3629         krwlock_t       *zl_rwlock;     /* lock we acquired */
3630         znode_t         *zl_znode;      /* znode we held */
3631         struct zfs_zlock *zl_next;      /* next in list */
3632 } zfs_zlock_t;
3633 
3634 /*
3635  * Drop locks and release vnodes that were held by zfs_rename_lock().
3636  */
3637 static void
3638 zfs_rename_unlock(zfs_zlock_t **zlpp)
3639 {
3640         zfs_zlock_t *zl;
3641 
3642         while ((zl = *zlpp) != NULL) {
3643                 if (zl->zl_znode != NULL)
3644                         VN_RELE(ZTOV(zl->zl_znode));
3645                 rw_exit(zl->zl_rwlock);
3646                 *zlpp = zl->zl_next;
3647                 kmem_free(zl, sizeof (*zl));
3648         }
3649 }
3650 
3651 /*
3652  * Search back through the directory tree, using the ".." entries.
3653  * Lock each directory in the chain to prevent concurrent renames.
3654  * Fail any attempt to move a directory into one of its own descendants.
3655  * XXX - z_parent_lock can overlap with map or grow locks
3656  */
3657 static int
3658 zfs_rename_lock(znode_t *szp, znode_t *tdzp, znode_t *sdzp, zfs_zlock_t **zlpp)
3659 {
3660         zfs_zlock_t     *zl;
3661         znode_t         *zp = tdzp;
3662         uint64_t        rootid = zp->z_zfsvfs->z_root;
3663         uint64_t        oidp = zp->z_id;
3664         krwlock_t       *rwlp = &szp->z_parent_lock;
3665         krw_t           rw = RW_WRITER;
3666 
3667         /*
3668          * First pass write-locks szp and compares to zp->z_id.
3669          * Later passes read-lock zp and compare to zp->z_parent.
3670          */
3671         do {
3672                 if (!rw_tryenter(rwlp, rw)) {
3673                         /*
3674                          * Another thread is renaming in this path.
3675                          * Note that if we are a WRITER, we don't have any
3676                          * parent_locks held yet.
3677                          */
3678                         if (rw == RW_READER && zp->z_id > szp->z_id) {
3679                                 /*
3680                                  * Drop our locks and restart
3681                                  */
3682                                 zfs_rename_unlock(&zl);
3683                                 *zlpp = NULL;
3684                                 zp = tdzp;
3685                                 oidp = zp->z_id;
3686                                 rwlp = &szp->z_parent_lock;
3687                                 rw = RW_WRITER;
3688                                 continue;
3689                         } else {
3690                                 /*
3691                                  * Wait for other thread to drop its locks
3692                                  */
3693                                 rw_enter(rwlp, rw);
3694                         }
3695                 }
3696 
3697                 zl = kmem_alloc(sizeof (*zl), KM_SLEEP);
3698                 zl->zl_rwlock = rwlp;
3699                 zl->zl_znode = NULL;
3700                 zl->zl_next = *zlpp;
3701                 *zlpp = zl;
3702 
3703                 if (oidp == szp->z_id)               /* We're a descendant of szp */
3704                         return (SET_ERROR(EINVAL));
3705 
3706                 if (oidp == rootid)             /* We've hit the top */
3707                         return (0);
3708 
3709                 if (rw == RW_READER) {          /* i.e. not the first pass */
3710                         int error = zfs_zget(zp->z_zfsvfs, oidp, &zp);
3711                         if (error)
3712                                 return (error);
3713                         zl->zl_znode = zp;
3714                 }
3715                 (void) sa_lookup(zp->z_sa_hdl, SA_ZPL_PARENT(zp->z_zfsvfs),
3716                     &oidp, sizeof (oidp));
3717                 rwlp = &zp->z_parent_lock;
3718                 rw = RW_READER;
3719 
3720         } while (zp->z_id != sdzp->z_id);
3721 
3722         return (0);
3723 }
3724 
3725 /*
3726  * Move an entry from the provided source directory to the target
3727  * directory.  Change the entry name as indicated.
3728  *
3729  *      IN:     sdvp    - Source directory containing the "old entry".
3730  *              snm     - Old entry name.
3731  *              tdvp    - Target directory to contain the "new entry".
3732  *              tnm     - New entry name.
3733  *              cr      - credentials of caller.
3734  *              ct      - caller context
3735  *              flags   - case flags
3736  *
3737  *      RETURN: 0 on success, error code on failure.
3738  *
3739  * Timestamps:
3740  *      sdvp,tdvp - ctime|mtime updated
3741  */
3742 /*ARGSUSED*/
3743 static int
3744 zfs_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, cred_t *cr,
3745     caller_context_t *ct, int flags)
3746 {
3747         znode_t         *tdzp, *szp, *tzp;
3748         znode_t         *sdzp = VTOZ(sdvp);
3749         zfsvfs_t        *zfsvfs = sdzp->z_zfsvfs;
3750         zilog_t         *zilog;
3751         vnode_t         *realvp;
3752         zfs_dirlock_t   *sdl, *tdl;
3753         dmu_tx_t        *tx;
3754         zfs_zlock_t     *zl;
3755         int             cmp, serr, terr;
3756         int             error = 0, rm_err = 0;
3757         int             zflg = 0;
3758         boolean_t       waited = B_FALSE;
3759 
3760         ZFS_ENTER(zfsvfs);
3761         ZFS_VERIFY_ZP(sdzp);
3762         zilog = zfsvfs->z_log;
3763 
3764         /*
3765          * Make sure we have the real vp for the target directory.
3766          */
3767         if (VOP_REALVP(tdvp, &realvp, ct) == 0)
3768                 tdvp = realvp;
3769 
3770         tdzp = VTOZ(tdvp);
3771         ZFS_VERIFY_ZP(tdzp);
3772 
3773         /*
3774          * We check z_zfsvfs rather than v_vfsp here, because snapshots and the
3775          * ctldir appear to have the same v_vfsp.
3776          */
3777         if (tdzp->z_zfsvfs != zfsvfs || zfsctl_is_node(tdvp)) {
3778                 ZFS_EXIT(zfsvfs);
3779                 return (SET_ERROR(EXDEV));
3780         }
3781 
3782         if (zfsvfs->z_utf8 && u8_validate(tnm,
3783             strlen(tnm), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
3784                 ZFS_EXIT(zfsvfs);
3785                 return (SET_ERROR(EILSEQ));
3786         }
3787 
3788         if (flags & FIGNORECASE)
3789                 zflg |= ZCILOOK;
3790 
3791 top:
3792         szp = NULL;
3793         tzp = NULL;
3794         zl = NULL;
3795 
3796         /*
3797          * This is to prevent the creation of links into attribute space
3798          * by renaming a linked file into/outof an attribute directory.
3799          * See the comment in zfs_link() for why this is considered bad.
3800          */
3801         if ((tdzp->z_pflags & ZFS_XATTR) != (sdzp->z_pflags & ZFS_XATTR)) {
3802                 ZFS_EXIT(zfsvfs);
3803                 return (SET_ERROR(EINVAL));
3804         }
3805 
3806         /*
3807          * Lock source and target directory entries.  To prevent deadlock,
3808          * a lock ordering must be defined.  We lock the directory with
3809          * the smallest object id first, or if it's a tie, the one with
3810          * the lexically first name.
3811          */
3812         if (sdzp->z_id < tdzp->z_id) {
3813                 cmp = -1;
3814         } else if (sdzp->z_id > tdzp->z_id) {
3815                 cmp = 1;
3816         } else {
3817                 /*
3818                  * First compare the two name arguments without
3819                  * considering any case folding.
3820                  */
3821                 int nofold = (zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER);
3822 
3823                 cmp = u8_strcmp(snm, tnm, 0, nofold, U8_UNICODE_LATEST, &error);
3824                 ASSERT(error == 0 || !zfsvfs->z_utf8);
3825                 if (cmp == 0) {
3826                         /*
3827                          * POSIX: "If the old argument and the new argument
3828                          * both refer to links to the same existing file,
3829                          * the rename() function shall return successfully
3830                          * and perform no other action."
3831                          */
3832                         ZFS_EXIT(zfsvfs);
3833                         return (0);
3834                 }
3835                 /*
3836                  * If the file system is case-folding, then we may
3837                  * have some more checking to do.  A case-folding file
3838                  * system is either supporting mixed case sensitivity
3839                  * access or is completely case-insensitive.  Note
3840                  * that the file system is always case preserving.
3841                  *
3842                  * In mixed sensitivity mode case sensitive behavior
3843                  * is the default.  FIGNORECASE must be used to
3844                  * explicitly request case insensitive behavior.
3845                  *
3846                  * If the source and target names provided differ only
3847                  * by case (e.g., a request to rename 'tim' to 'Tim'),
3848                  * we will treat this as a special case in the
3849                  * case-insensitive mode: as long as the source name
3850                  * is an exact match, we will allow this to proceed as
3851                  * a name-change request.
3852                  */
3853                 if ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE ||
3854                     (zfsvfs->z_case == ZFS_CASE_MIXED &&
3855                     flags & FIGNORECASE)) &&
3856                     u8_strcmp(snm, tnm, 0, zfsvfs->z_norm, U8_UNICODE_LATEST,
3857                     &error) == 0) {
3858                         /*
3859                          * case preserving rename request, require exact
3860                          * name matches
3861                          */
3862                         zflg |= ZCIEXACT;
3863                         zflg &= ~ZCILOOK;
3864                 }
3865         }
3866 
3867         /*
3868          * If the source and destination directories are the same, we should
3869          * grab the z_name_lock of that directory only once.
3870          */
3871         if (sdzp == tdzp) {
3872                 zflg |= ZHAVELOCK;
3873                 rw_enter(&sdzp->z_name_lock, RW_READER);
3874         }
3875 
3876         if (cmp < 0) {
3877                 serr = zfs_dirent_lock(&sdl, sdzp, snm, &szp,
3878                     ZEXISTS | zflg, NULL, NULL);
3879                 terr = zfs_dirent_lock(&tdl,
3880                     tdzp, tnm, &tzp, ZRENAMING | zflg, NULL, NULL);
3881         } else {
3882                 terr = zfs_dirent_lock(&tdl,
3883                     tdzp, tnm, &tzp, zflg, NULL, NULL);
3884                 serr = zfs_dirent_lock(&sdl,
3885                     sdzp, snm, &szp, ZEXISTS | ZRENAMING | zflg,
3886                     NULL, NULL);
3887         }
3888 
3889         if (serr) {
3890                 /*
3891                  * Source entry invalid or not there.
3892                  */
3893                 if (!terr) {
3894                         zfs_dirent_unlock(tdl);
3895                         if (tzp)
3896                                 VN_RELE(ZTOV(tzp));
3897                 }
3898 
3899                 if (sdzp == tdzp)
3900                         rw_exit(&sdzp->z_name_lock);
3901 
3902                 if (strcmp(snm, "..") == 0)
3903                         serr = SET_ERROR(EINVAL);
3904                 ZFS_EXIT(zfsvfs);
3905                 return (serr);
3906         }
3907         if (terr) {
3908                 zfs_dirent_unlock(sdl);
3909                 VN_RELE(ZTOV(szp));
3910 
3911                 if (sdzp == tdzp)
3912                         rw_exit(&sdzp->z_name_lock);
3913 
3914                 if (strcmp(tnm, "..") == 0)
3915                         terr = SET_ERROR(EINVAL);
3916                 ZFS_EXIT(zfsvfs);
3917                 return (terr);
3918         }
3919 
3920         /*
3921          * Must have write access at the source to remove the old entry
3922          * and write access at the target to create the new entry.
3923          * Note that if target and source are the same, this can be
3924          * done in a single check.
3925          */
3926 
3927         if (error = zfs_zaccess_rename(sdzp, szp, tdzp, tzp, cr))
3928                 goto out;
3929 
3930         if (ZTOV(szp)->v_type == VDIR) {
3931                 /*
3932                  * Check to make sure rename is valid.
3933                  * Can't do a move like this: /usr/a/b to /usr/a/b/c/d
3934                  */
3935                 if (error = zfs_rename_lock(szp, tdzp, sdzp, &zl))
3936                         goto out;
3937         }
3938 
3939         /*
3940          * Does target exist?
3941          */
3942         if (tzp) {
3943                 /*
3944                  * Source and target must be the same type.
3945                  */
3946                 if (ZTOV(szp)->v_type == VDIR) {
3947                         if (ZTOV(tzp)->v_type != VDIR) {
3948                                 error = SET_ERROR(ENOTDIR);
3949                                 goto out;
3950                         }
3951                 } else {
3952                         if (ZTOV(tzp)->v_type == VDIR) {
3953                                 error = SET_ERROR(EISDIR);
3954                                 goto out;
3955                         }
3956                 }
3957                 /*
3958                  * POSIX dictates that when the source and target
3959                  * entries refer to the same file object, rename
3960                  * must do nothing and exit without error.
3961                  */
3962                 if (szp->z_id == tzp->z_id) {
3963                         error = 0;
3964                         goto out;
3965                 }
3966         }
3967 
3968         vnevent_pre_rename_src(ZTOV(szp), sdvp, snm, ct);
3969         if (tzp)
3970                 vnevent_pre_rename_dest(ZTOV(tzp), tdvp, tnm, ct);
3971 
3972         /*
3973          * notify the target directory if it is not the same
3974          * as source directory.
3975          */
3976         if (tdvp != sdvp) {
3977                 vnevent_pre_rename_dest_dir(tdvp, ZTOV(szp), tnm, ct);
3978         }
3979 
3980         tx = dmu_tx_create(zfsvfs->z_os);
3981         dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
3982         dmu_tx_hold_sa(tx, sdzp->z_sa_hdl, B_FALSE);
3983         dmu_tx_hold_zap(tx, sdzp->z_id, FALSE, snm);
3984         dmu_tx_hold_zap(tx, tdzp->z_id, TRUE, tnm);
3985         if (sdzp != tdzp) {
3986                 dmu_tx_hold_sa(tx, tdzp->z_sa_hdl, B_FALSE);
3987                 zfs_sa_upgrade_txholds(tx, tdzp);
3988         }
3989         if (tzp) {
3990                 dmu_tx_hold_sa(tx, tzp->z_sa_hdl, B_FALSE);
3991                 zfs_sa_upgrade_txholds(tx, tzp);
3992         }
3993 
3994         zfs_sa_upgrade_txholds(tx, szp);
3995         dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
3996         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
3997         if (error) {
3998                 if (zl != NULL)
3999                         zfs_rename_unlock(&zl);
4000                 zfs_dirent_unlock(sdl);
4001                 zfs_dirent_unlock(tdl);
4002 
4003                 if (sdzp == tdzp)
4004                         rw_exit(&sdzp->z_name_lock);
4005 
4006                 VN_RELE(ZTOV(szp));
4007                 if (tzp)
4008                         VN_RELE(ZTOV(tzp));
4009                 if (error == ERESTART) {
4010                         waited = B_TRUE;
4011                         dmu_tx_wait(tx);
4012                         dmu_tx_abort(tx);
4013                         goto top;
4014                 }
4015                 dmu_tx_abort(tx);
4016                 ZFS_EXIT(zfsvfs);
4017                 return (error);
4018         }
4019 
4020         if (tzp)        /* Attempt to remove the existing target */
4021                 error = rm_err = zfs_link_destroy(tdl, tzp, tx, zflg, NULL);
4022 
4023         if (error == 0) {
4024                 error = zfs_link_create(tdl, szp, tx, ZRENAMING);
4025                 if (error == 0) {
4026                         szp->z_pflags |= ZFS_AV_MODIFIED;
4027 
4028                         error = sa_update(szp->z_sa_hdl, SA_ZPL_FLAGS(zfsvfs),
4029                             (void *)&szp->z_pflags, sizeof (uint64_t), tx);
4030                         ASSERT0(error);
4031 
4032                         error = zfs_link_destroy(sdl, szp, tx, ZRENAMING, NULL);
4033                         if (error == 0) {
4034                                 zfs_log_rename(zilog, tx, TX_RENAME |
4035                                     (flags & FIGNORECASE ? TX_CI : 0), sdzp,
4036                                     sdl->dl_name, tdzp, tdl->dl_name, szp);
4037 
4038                                 /*
4039                                  * Update path information for the target vnode
4040                                  */
4041                                 vn_renamepath(tdvp, ZTOV(szp), tnm,
4042                                     strlen(tnm));
4043                         } else {
4044                                 /*
4045                                  * At this point, we have successfully created
4046                                  * the target name, but have failed to remove
4047                                  * the source name.  Since the create was done
4048                                  * with the ZRENAMING flag, there are
4049                                  * complications; for one, the link count is
4050                                  * wrong.  The easiest way to deal with this
4051                                  * is to remove the newly created target, and
4052                                  * return the original error.  This must
4053                                  * succeed; fortunately, it is very unlikely to
4054                                  * fail, since we just created it.
4055                                  */
4056                                 VERIFY3U(zfs_link_destroy(tdl, szp, tx,
4057                                     ZRENAMING, NULL), ==, 0);
4058                         }
4059                 }
4060         }
4061 
4062         dmu_tx_commit(tx);
4063 
4064         if (tzp && rm_err == 0)
4065                 vnevent_rename_dest(ZTOV(tzp), tdvp, tnm, ct);
4066 
4067         if (error == 0) {
4068                 vnevent_rename_src(ZTOV(szp), sdvp, snm, ct);
4069                 /* notify the target dir if it is not the same as source dir */
4070                 if (tdvp != sdvp)
4071                         vnevent_rename_dest_dir(tdvp, ct);
4072         }
4073 out:
4074         if (zl != NULL)
4075                 zfs_rename_unlock(&zl);
4076 
4077         zfs_dirent_unlock(sdl);
4078         zfs_dirent_unlock(tdl);
4079 
4080         if (sdzp == tdzp)
4081                 rw_exit(&sdzp->z_name_lock);
4082 
4083 
4084         VN_RELE(ZTOV(szp));
4085         if (tzp)
4086                 VN_RELE(ZTOV(tzp));
4087 
4088         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4089                 zil_commit(zilog, 0);
4090 
4091         ZFS_EXIT(zfsvfs);
4092         return (error);
4093 }
4094 
4095 /*
4096  * Insert the indicated symbolic reference entry into the directory.
4097  *
4098  *      IN:     dvp     - Directory to contain new symbolic link.
4099  *              link    - Name for new symlink entry.
4100  *              vap     - Attributes of new entry.
4101  *              cr      - credentials of caller.
4102  *              ct      - caller context
4103  *              flags   - case flags
4104  *
4105  *      RETURN: 0 on success, error code on failure.
4106  *
4107  * Timestamps:
4108  *      dvp - ctime|mtime updated
4109  */
4110 /*ARGSUSED*/
4111 static int
4112 zfs_symlink(vnode_t *dvp, char *name, vattr_t *vap, char *link, cred_t *cr,
4113     caller_context_t *ct, int flags)
4114 {
4115         znode_t         *zp, *dzp = VTOZ(dvp);
4116         zfs_dirlock_t   *dl;
4117         dmu_tx_t        *tx;
4118         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
4119         zilog_t         *zilog;
4120         int             imm_was_set = 0;
4121         uint64_t        len = strlen(link);
4122         int             error;
4123         int             zflg = ZNEW;
4124         zfs_acl_ids_t   acl_ids;
4125         boolean_t       fuid_dirtied;
4126         uint64_t        txtype = TX_SYMLINK;
4127         boolean_t       waited = B_FALSE;
4128 
4129         ASSERT(vap->va_type == VLNK);
4130 
4131         ZFS_ENTER(zfsvfs);
4132         ZFS_VERIFY_ZP(dzp);
4133         zilog = zfsvfs->z_log;
4134 
4135         if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
4136             NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
4137                 ZFS_EXIT(zfsvfs);
4138                 return (SET_ERROR(EILSEQ));
4139         }
4140         if (flags & FIGNORECASE)
4141                 zflg |= ZCILOOK;
4142 
4143         if (len > MAXPATHLEN) {
4144                 ZFS_EXIT(zfsvfs);
4145                 return (SET_ERROR(ENAMETOOLONG));
4146         }
4147 
4148         if ((error = zfs_acl_ids_create(dzp, 0,
4149             vap, cr, NULL, &acl_ids)) != 0) {
4150                 ZFS_EXIT(zfsvfs);
4151                 return (error);
4152         }
4153 top:
4154         /*
4155          * Attempt to lock directory; fail if entry already exists.
4156          */
4157         error = zfs_dirent_lock(&dl, dzp, name, &zp, zflg, NULL, NULL);
4158         if (error) {
4159                 zfs_acl_ids_free(&acl_ids);
4160                 ZFS_EXIT(zfsvfs);
4161                 return (error);
4162         }
4163 
4164         if ((dzp->z_pflags & ZFS_IMMUTABLE) && dzp->z_zfsvfs->z_isworm) {
4165                 imm_was_set = 1;
4166                 dzp->z_pflags &= ~ZFS_IMMUTABLE;
4167         }
4168         if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
4169                 if (imm_was_set)
4170                         dzp->z_pflags |= ZFS_IMMUTABLE;
4171                 zfs_acl_ids_free(&acl_ids);
4172                 zfs_dirent_unlock(dl);
4173                 ZFS_EXIT(zfsvfs);
4174                 return (error);
4175         }
4176         if (imm_was_set)
4177                 dzp->z_pflags |= ZFS_IMMUTABLE;
4178 
4179         if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
4180                 zfs_acl_ids_free(&acl_ids);
4181                 zfs_dirent_unlock(dl);
4182                 ZFS_EXIT(zfsvfs);
4183                 return (SET_ERROR(EDQUOT));
4184         }
4185         tx = dmu_tx_create(zfsvfs->z_os);
4186         fuid_dirtied = zfsvfs->z_fuid_dirty;
4187         dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, MAX(1, len));
4188         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
4189         dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
4190             ZFS_SA_BASE_ATTR_SIZE + len);
4191         dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
4192         if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
4193                 dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
4194                     acl_ids.z_aclp->z_acl_bytes);
4195         }
4196         if (fuid_dirtied)
4197                 zfs_fuid_txhold(zfsvfs, tx);
4198         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
4199         if (error) {
4200                 zfs_dirent_unlock(dl);
4201                 if (error == ERESTART) {
4202                         waited = B_TRUE;
4203                         dmu_tx_wait(tx);
4204                         dmu_tx_abort(tx);
4205                         goto top;
4206                 }
4207                 zfs_acl_ids_free(&acl_ids);
4208                 dmu_tx_abort(tx);
4209                 ZFS_EXIT(zfsvfs);
4210                 return (error);
4211         }
4212 
4213         /*
4214          * Create a new object for the symlink.
4215          * for version 4 ZPL datsets the symlink will be an SA attribute
4216          */
4217         zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
4218 
4219         if (fuid_dirtied)
4220                 zfs_fuid_sync(zfsvfs, tx);
4221 
4222         mutex_enter(&zp->z_lock);
4223         if (zp->z_is_sa)
4224                 error = sa_update(zp->z_sa_hdl, SA_ZPL_SYMLINK(zfsvfs),
4225                     link, len, tx);
4226         else
4227                 zfs_sa_symlink(zp, link, len, tx);
4228         mutex_exit(&zp->z_lock);
4229 
4230         zp->z_size = len;
4231         (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
4232             &zp->z_size, sizeof (zp->z_size), tx);
4233         /*
4234          * Insert the new object into the directory.
4235          */
4236         (void) zfs_link_create(dl, zp, tx, ZNEW);
4237 
4238         if (flags & FIGNORECASE)
4239                 txtype |= TX_CI;
4240         zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
4241 
4242         zfs_acl_ids_free(&acl_ids);
4243 
4244         dmu_tx_commit(tx);
4245 
4246         zfs_dirent_unlock(dl);
4247 
4248         VN_RELE(ZTOV(zp));
4249 
4250         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4251                 zil_commit(zilog, 0);
4252 
4253         ZFS_EXIT(zfsvfs);
4254         return (error);
4255 }
4256 
4257 /*
4258  * Return, in the buffer contained in the provided uio structure,
4259  * the symbolic path referred to by vp.
4260  *
4261  *      IN:     vp      - vnode of symbolic link.
4262  *              uio     - structure to contain the link path.
4263  *              cr      - credentials of caller.
4264  *              ct      - caller context
4265  *
4266  *      OUT:    uio     - structure containing the link path.
4267  *
4268  *      RETURN: 0 on success, error code on failure.
4269  *
4270  * Timestamps:
4271  *      vp - atime updated
4272  */
4273 /* ARGSUSED */
4274 static int
4275 zfs_readlink(vnode_t *vp, uio_t *uio, cred_t *cr, caller_context_t *ct)
4276 {
4277         znode_t         *zp = VTOZ(vp);
4278         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4279         int             error;
4280 
4281         ZFS_ENTER(zfsvfs);
4282         ZFS_VERIFY_ZP(zp);
4283 
4284         mutex_enter(&zp->z_lock);
4285         if (zp->z_is_sa)
4286                 error = sa_lookup_uio(zp->z_sa_hdl,
4287                     SA_ZPL_SYMLINK(zfsvfs), uio);
4288         else
4289                 error = zfs_sa_readlink(zp, uio);
4290         mutex_exit(&zp->z_lock);
4291 
4292         ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
4293 
4294         ZFS_EXIT(zfsvfs);
4295         return (error);
4296 }
4297 
4298 /*
4299  * Insert a new entry into directory tdvp referencing svp.
4300  *
4301  *      IN:     tdvp    - Directory to contain new entry.
4302  *              svp     - vnode of new entry.
4303  *              name    - name of new entry.
4304  *              cr      - credentials of caller.
4305  *              ct      - caller context
4306  *
4307  *      RETURN: 0 on success, error code on failure.
4308  *
4309  * Timestamps:
4310  *      tdvp - ctime|mtime updated
4311  *       svp - ctime updated
4312  */
4313 /* ARGSUSED */
4314 static int
4315 zfs_link(vnode_t *tdvp, vnode_t *svp, char *name, cred_t *cr,
4316     caller_context_t *ct, int flags)
4317 {
4318         znode_t         *dzp = VTOZ(tdvp);
4319         znode_t         *tzp, *szp;
4320         zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
4321         zilog_t         *zilog;
4322         zfs_dirlock_t   *dl;
4323         dmu_tx_t        *tx;
4324         vnode_t         *realvp;
4325         int             error;
4326         int             zf = ZNEW;
4327         uint64_t        parent;
4328         uid_t           owner;
4329         boolean_t       waited = B_FALSE;
4330 
4331         ASSERT(tdvp->v_type == VDIR);
4332 
4333         ZFS_ENTER(zfsvfs);
4334         ZFS_VERIFY_ZP(dzp);
4335         zilog = zfsvfs->z_log;
4336 
4337         if (VOP_REALVP(svp, &realvp, ct) == 0)
4338                 svp = realvp;
4339 
4340         /*
4341          * POSIX dictates that we return EPERM here.
4342          * Better choices include ENOTSUP or EISDIR.
4343          */
4344         if (svp->v_type == VDIR) {
4345                 ZFS_EXIT(zfsvfs);
4346                 return (SET_ERROR(EPERM));
4347         }
4348 
4349         szp = VTOZ(svp);
4350         ZFS_VERIFY_ZP(szp);
4351 
4352         /*
4353          * We check z_zfsvfs rather than v_vfsp here, because snapshots and the
4354          * ctldir appear to have the same v_vfsp.
4355          */
4356         if (szp->z_zfsvfs != zfsvfs || zfsctl_is_node(svp)) {
4357                 ZFS_EXIT(zfsvfs);
4358                 return (SET_ERROR(EXDEV));
4359         }
4360 
4361         /* Prevent links to .zfs/shares files */
4362 
4363         if ((error = sa_lookup(szp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
4364             &parent, sizeof (uint64_t))) != 0) {
4365                 ZFS_EXIT(zfsvfs);
4366                 return (error);
4367         }
4368         if (parent == zfsvfs->z_shares_dir) {
4369                 ZFS_EXIT(zfsvfs);
4370                 return (SET_ERROR(EPERM));
4371         }
4372 
4373         if (zfsvfs->z_utf8 && u8_validate(name,
4374             strlen(name), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
4375                 ZFS_EXIT(zfsvfs);
4376                 return (SET_ERROR(EILSEQ));
4377         }
4378         if (flags & FIGNORECASE)
4379                 zf |= ZCILOOK;
4380 
4381         /*
4382          * We do not support links between attributes and non-attributes
4383          * because of the potential security risk of creating links
4384          * into "normal" file space in order to circumvent restrictions
4385          * imposed in attribute space.
4386          */
4387         if ((szp->z_pflags & ZFS_XATTR) != (dzp->z_pflags & ZFS_XATTR)) {
4388                 ZFS_EXIT(zfsvfs);
4389                 return (SET_ERROR(EINVAL));
4390         }
4391 
4392 
4393         owner = zfs_fuid_map_id(zfsvfs, szp->z_uid, cr, ZFS_OWNER);
4394         if (owner != crgetuid(cr) && secpolicy_basic_link(cr) != 0) {
4395                 ZFS_EXIT(zfsvfs);
4396                 return (SET_ERROR(EPERM));
4397         }
4398 
4399         if (error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr)) {
4400                 ZFS_EXIT(zfsvfs);
4401                 return (error);
4402         }
4403 
4404 top:
4405         /*
4406          * Attempt to lock directory; fail if entry already exists.
4407          */
4408         error = zfs_dirent_lock(&dl, dzp, name, &tzp, zf, NULL, NULL);
4409         if (error) {
4410                 ZFS_EXIT(zfsvfs);
4411                 return (error);
4412         }
4413 
4414         tx = dmu_tx_create(zfsvfs->z_os);
4415         dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
4416         dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
4417         zfs_sa_upgrade_txholds(tx, szp);
4418         zfs_sa_upgrade_txholds(tx, dzp);
4419         error = dmu_tx_assign(tx, waited ? TXG_WAITED : TXG_NOWAIT);
4420         if (error) {
4421                 zfs_dirent_unlock(dl);
4422                 if (error == ERESTART) {
4423                         waited = B_TRUE;
4424                         dmu_tx_wait(tx);
4425                         dmu_tx_abort(tx);
4426                         goto top;
4427                 }
4428                 dmu_tx_abort(tx);
4429                 ZFS_EXIT(zfsvfs);
4430                 return (error);
4431         }
4432 
4433         error = zfs_link_create(dl, szp, tx, 0);
4434 
4435         if (error == 0) {
4436                 uint64_t txtype = TX_LINK;
4437                 if (flags & FIGNORECASE)
4438                         txtype |= TX_CI;
4439                 zfs_log_link(zilog, tx, txtype, dzp, szp, name);
4440         }
4441 
4442         dmu_tx_commit(tx);
4443 
4444         zfs_dirent_unlock(dl);
4445 
4446         if (error == 0) {
4447                 vnevent_link(svp, ct);
4448         }
4449 
4450         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4451                 zil_commit(zilog, 0);
4452 
4453         ZFS_EXIT(zfsvfs);
4454         return (error);
4455 }
4456 
4457 /*
4458  * zfs_null_putapage() is used when the file system has been force
4459  * unmounted. It just drops the pages.
4460  */
4461 /* ARGSUSED */
4462 static int
4463 zfs_null_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
4464     size_t *lenp, int flags, cred_t *cr)
4465 {
4466         pvn_write_done(pp, B_INVAL|B_FORCE|B_ERROR);
4467         return (0);
4468 }
4469 
4470 /*
4471  * Push a page out to disk, klustering if possible.
4472  *
4473  *      IN:     vp      - file to push page to.
4474  *              pp      - page to push.
4475  *              flags   - additional flags.
4476  *              cr      - credentials of caller.
4477  *
4478  *      OUT:    offp    - start of range pushed.
4479  *              lenp    - len of range pushed.
4480  *
4481  *      RETURN: 0 on success, error code on failure.
4482  *
4483  * NOTE: callers must have locked the page to be pushed.  On
4484  * exit, the page (and all other pages in the kluster) must be
4485  * unlocked.
4486  */
4487 /* ARGSUSED */
4488 static int
4489 zfs_putapage(vnode_t *vp, page_t *pp, u_offset_t *offp,
4490     size_t *lenp, int flags, cred_t *cr)
4491 {
4492         znode_t         *zp = VTOZ(vp);
4493         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4494         dmu_tx_t        *tx;
4495         u_offset_t      off, koff;
4496         size_t          len, klen;
4497         int             err;
4498 
4499         off = pp->p_offset;
4500         len = PAGESIZE;
4501         /*
4502          * If our blocksize is bigger than the page size, try to kluster
4503          * multiple pages so that we write a full block (thus avoiding
4504          * a read-modify-write).
4505          */
4506         if (off < zp->z_size && zp->z_blksz > PAGESIZE) {
4507                 klen = P2ROUNDUP((ulong_t)zp->z_blksz, PAGESIZE);
4508                 koff = ISP2(klen) ? P2ALIGN(off, (u_offset_t)klen) : 0;
4509                 ASSERT(koff <= zp->z_size);
4510                 if (koff + klen > zp->z_size)
4511                         klen = P2ROUNDUP(zp->z_size - koff, (uint64_t)PAGESIZE);
4512                 pp = pvn_write_kluster(vp, pp, &off, &len, koff, klen, flags);
4513         }
4514         ASSERT3U(btop(len), ==, btopr(len));
4515 
4516         /*
4517          * Can't push pages past end-of-file.
4518          */
4519         if (off >= zp->z_size) {
4520                 /* ignore all pages */
4521                 err = 0;
4522                 goto out;
4523         } else if (off + len > zp->z_size) {
4524                 int npages = btopr(zp->z_size - off);
4525                 page_t *trunc;
4526 
4527                 page_list_break(&pp, &trunc, npages);
4528                 /* ignore pages past end of file */
4529                 if (trunc)
4530                         pvn_write_done(trunc, flags);
4531                 len = zp->z_size - off;
4532         }
4533 
4534         if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
4535             zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {
4536                 err = SET_ERROR(EDQUOT);
4537                 goto out;
4538         }
4539         tx = dmu_tx_create(zfsvfs->z_os);
4540         dmu_tx_hold_write(tx, zp->z_id, off, len);
4541 
4542         dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
4543         zfs_sa_upgrade_txholds(tx, zp);
4544         err = dmu_tx_assign(tx, TXG_WAIT);
4545         if (err != 0) {
4546                 dmu_tx_abort(tx);
4547                 goto out;
4548         }
4549 
4550         if (zp->z_blksz <= PAGESIZE) {
4551                 caddr_t va = zfs_map_page(pp, S_READ);
4552                 ASSERT3U(len, <=, PAGESIZE);
4553                 dmu_write(zfsvfs->z_os, zp->z_id, off, len, va, tx);
4554                 zfs_unmap_page(pp, va);
4555         } else {
4556                 err = dmu_write_pages(zfsvfs->z_os, zp->z_id, off, len, pp, tx);
4557         }
4558 
4559         if (err == 0) {
4560                 uint64_t mtime[2], ctime[2];
4561                 sa_bulk_attr_t bulk[3];
4562                 int count = 0;
4563 
4564                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
4565                     &mtime, 16);
4566                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
4567                     &ctime, 16);
4568                 SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
4569                     &zp->z_pflags, 8);
4570                 zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime,
4571                     B_TRUE);
4572                 err = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
4573                 ASSERT0(err);
4574                 zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, off, len, 0);
4575         }
4576         dmu_tx_commit(tx);
4577 
4578 out:
4579         pvn_write_done(pp, (err ? B_ERROR : 0) | flags);
4580         if (offp)
4581                 *offp = off;
4582         if (lenp)
4583                 *lenp = len;
4584 
4585         return (err);
4586 }
4587 
4588 /*
4589  * Copy the portion of the file indicated from pages into the file.
4590  * The pages are stored in a page list attached to the files vnode.
4591  *
4592  *      IN:     vp      - vnode of file to push page data to.
4593  *              off     - position in file to put data.
4594  *              len     - amount of data to write.
4595  *              flags   - flags to control the operation.
4596  *              cr      - credentials of caller.
4597  *              ct      - caller context.
4598  *
4599  *      RETURN: 0 on success, error code on failure.
4600  *
4601  * Timestamps:
4602  *      vp - ctime|mtime updated
4603  */
4604 /*ARGSUSED*/
4605 static int
4606 zfs_putpage(vnode_t *vp, offset_t off, size_t len, int flags, cred_t *cr,
4607     caller_context_t *ct)
4608 {
4609         znode_t         *zp = VTOZ(vp);
4610         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4611         page_t          *pp;
4612         size_t          io_len;
4613         u_offset_t      io_off;
4614         uint_t          blksz;
4615         rl_t            *rl;
4616         int             error = 0;
4617 
4618         ZFS_ENTER(zfsvfs);
4619         ZFS_VERIFY_ZP(zp);
4620 
4621         /*
4622          * There's nothing to do if no data is cached.
4623          */
4624         if (!vn_has_cached_data(vp)) {
4625                 ZFS_EXIT(zfsvfs);
4626                 return (0);
4627         }
4628 
4629         /*
4630          * Align this request to the file block size in case we kluster.
4631          * XXX - this can result in pretty aggresive locking, which can
4632          * impact simultanious read/write access.  One option might be
4633          * to break up long requests (len == 0) into block-by-block
4634          * operations to get narrower locking.
4635          */
4636         blksz = zp->z_blksz;
4637         if (ISP2(blksz))
4638                 io_off = P2ALIGN_TYPED(off, blksz, u_offset_t);
4639         else
4640                 io_off = 0;
4641         if (len > 0 && ISP2(blksz))
4642                 io_len = P2ROUNDUP_TYPED(len + (off - io_off), blksz, size_t);
4643         else
4644                 io_len = 0;
4645 
4646         if (io_len == 0) {
4647                 /*
4648                  * Search the entire vp list for pages >= io_off.
4649                  */
4650                 rl = zfs_range_lock(zp, io_off, UINT64_MAX, RL_WRITER);
4651                 error = pvn_vplist_dirty(vp, io_off, zfs_putapage, flags, cr);
4652                 goto out;
4653         }
4654         rl = zfs_range_lock(zp, io_off, io_len, RL_WRITER);
4655 
4656         if (off > zp->z_size) {
4657                 /* past end of file */
4658                 zfs_range_unlock(rl);
4659                 ZFS_EXIT(zfsvfs);
4660                 return (0);
4661         }
4662 
4663         len = MIN(io_len, P2ROUNDUP(zp->z_size, PAGESIZE) - io_off);
4664 
4665         for (off = io_off; io_off < off + len; io_off += io_len) {
4666                 if ((flags & B_INVAL) || ((flags & B_ASYNC) == 0)) {
4667                         pp = page_lookup(vp, io_off,
4668                             (flags & (B_INVAL | B_FREE)) ? SE_EXCL : SE_SHARED);
4669                 } else {
4670                         pp = page_lookup_nowait(vp, io_off,
4671                             (flags & B_FREE) ? SE_EXCL : SE_SHARED);
4672                 }
4673 
4674                 if (pp != NULL && pvn_getdirty(pp, flags)) {
4675                         int err;
4676 
4677                         /*
4678                          * Found a dirty page to push
4679                          */
4680                         err = zfs_putapage(vp, pp, &io_off, &io_len, flags, cr);
4681                         if (err)
4682                                 error = err;
4683                 } else {
4684                         io_len = PAGESIZE;
4685                 }
4686         }
4687 out:
4688         zfs_range_unlock(rl);
4689         if ((flags & B_ASYNC) == 0 || zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
4690                 zil_commit(zfsvfs->z_log, zp->z_id);
4691         ZFS_EXIT(zfsvfs);
4692         return (error);
4693 }
4694 
4695 /*
4696  * Returns B_TRUE and exits the z_teardown_inactive_lock
4697  * if the znode we are looking at is no longer valid
4698  */
4699 static boolean_t
4700 zfs_znode_free_invalid(znode_t *zp)
4701 {
4702         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4703         vnode_t *vp = ZTOV(zp);
4704 
4705         ASSERT(rw_read_held(&zfsvfs->z_teardown_inactive_lock));
4706 
4707         if (zp->z_sa_hdl == NULL) {
4708                 /*
4709                  * The fs has been unmounted, or we did a
4710                  * suspend/resume and this file no longer exists.
4711                  */
4712                 if (vn_has_cached_data(vp)) {
4713                         (void) pvn_vplist_dirty(vp, 0, zfs_null_putapage,
4714                             B_INVAL, CRED());
4715                 }
4716 
4717                 mutex_enter(&zp->z_lock);
4718                 mutex_enter(&vp->v_lock);
4719                 ASSERT(vp->v_count == 1);
4720                 VN_RELE_LOCKED(vp);
4721                 mutex_exit(&vp->v_lock);
4722                 mutex_exit(&zp->z_lock);
4723                 VERIFY(atomic_dec_32_nv(&zfsvfs->z_znodes_freeing_cnt) !=
4724                     UINT32_MAX);
4725                 rw_exit(&zfsvfs->z_teardown_inactive_lock);
4726                 zfs_znode_free(zp);
4727                 return (B_TRUE);
4728         }
4729 
4730         return (B_FALSE);
4731 }
4732 
4733 /*
4734  * Does the prep work for freeing the znode, then calls zfs_zinactive to do the
4735  * actual freeing.
4736  * This code used be in zfs_inactive() before the async delete patch came in
4737  */
4738 static void
4739 zfs_inactive_impl(znode_t *zp)
4740 {
4741         vnode_t *vp = ZTOV(zp);
4742         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4743         int error;
4744 
4745         rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_READER_STARVEWRITER);
4746         if (zfs_znode_free_invalid(zp))
4747                 return; /* z_teardown_inactive_lock already dropped */
4748 
4749         /*
4750          * Attempt to push any data in the page cache.  If this fails
4751          * we will get kicked out later in zfs_zinactive().
4752          */
4753         if (vn_has_cached_data(vp)) {
4754                 (void) pvn_vplist_dirty(vp, 0, zfs_putapage, B_INVAL|B_ASYNC,
4755                     CRED());
4756         }
4757 
4758         if (zp->z_atime_dirty && zp->z_unlinked == 0) {
4759                 dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os);
4760 
4761                 dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
4762                 zfs_sa_upgrade_txholds(tx, zp);
4763                 error = dmu_tx_assign(tx, TXG_WAIT);
4764                 if (error) {
4765                         dmu_tx_abort(tx);
4766                 } else {
4767                         mutex_enter(&zp->z_lock);
4768                         (void) sa_update(zp->z_sa_hdl, SA_ZPL_ATIME(zfsvfs),
4769                             (void *)&zp->z_atime, sizeof (zp->z_atime), tx);
4770                         zp->z_atime_dirty = 0;
4771                         mutex_exit(&zp->z_lock);
4772                         dmu_tx_commit(tx);
4773                 }
4774         }
4775 
4776         zfs_zinactive(zp);
4777 
4778         VERIFY(atomic_dec_32_nv(&zfsvfs->z_znodes_freeing_cnt) != UINT32_MAX);
4779 
4780         rw_exit(&zfsvfs->z_teardown_inactive_lock);
4781 }
4782 
4783 /*
4784  * taskq task calls zfs_inactive_impl() so that we can free the znode
4785  */
4786 static void
4787 zfs_inactive_task(void *task_arg)
4788 {
4789         znode_t *zp = task_arg;
4790         ASSERT(zp != NULL);
4791         zfs_inactive_impl(zp);
4792 }
4793 
4794 /*ARGSUSED*/
4795 void
4796 zfs_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
4797 {
4798         znode_t *zp = VTOZ(vp);
4799         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4800 
4801         rw_enter(&zfsvfs->z_teardown_inactive_lock, RW_READER_STARVEWRITER);
4802 
4803         VERIFY(atomic_inc_32_nv(&zfsvfs->z_znodes_freeing_cnt) != 0);
4804 
4805         if (zfs_znode_free_invalid(zp))
4806                 return; /* z_teardown_inactive_lock already dropped */
4807 
4808         if (zfs_do_async_free &&
4809             zp->z_size > zfs_inactive_async_multiplier * zfs_dirty_data_max &&
4810             taskq_dispatch(dsl_pool_vnrele_taskq(
4811             dmu_objset_pool(zp->z_zfsvfs->z_os)), zfs_inactive_task,
4812             zp, TQ_NOSLEEP) != NULL) {
4813                 rw_exit(&zfsvfs->z_teardown_inactive_lock);
4814                 return; /* task dispatched, we're done */
4815         }
4816         rw_exit(&zfsvfs->z_teardown_inactive_lock);
4817 
4818         /* if the taskq dispatch failed - do a sync zfs_inactive_impl() call */
4819         zfs_inactive_impl(zp);
4820 }
4821 
4822 /*
4823  * Bounds-check the seek operation.
4824  *
4825  *      IN:     vp      - vnode seeking within
4826  *              ooff    - old file offset
4827  *              noffp   - pointer to new file offset
4828  *              ct      - caller context
4829  *
4830  *      RETURN: 0 on success, EINVAL if new offset invalid.
4831  */
4832 /* ARGSUSED */
4833 static int
4834 zfs_seek(vnode_t *vp, offset_t ooff, offset_t *noffp,
4835     caller_context_t *ct)
4836 {
4837         if (vp->v_type == VDIR)
4838                 return (0);
4839         return ((*noffp < 0 || *noffp > MAXOFFSET_T) ? EINVAL : 0);
4840 }
4841 
4842 /*
4843  * Pre-filter the generic locking function to trap attempts to place
4844  * a mandatory lock on a memory mapped file.
4845  */
4846 static int
4847 zfs_frlock(vnode_t *vp, int cmd, flock64_t *bfp, int flag, offset_t offset,
4848     flk_callback_t *flk_cbp, cred_t *cr, caller_context_t *ct)
4849 {
4850         znode_t *zp = VTOZ(vp);
4851         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
4852 
4853         ZFS_ENTER(zfsvfs);
4854         ZFS_VERIFY_ZP(zp);
4855 
4856         /*
4857          * We are following the UFS semantics with respect to mapcnt
4858          * here: If we see that the file is mapped already, then we will
4859          * return an error, but we don't worry about races between this
4860          * function and zfs_map().
4861          */
4862         if (zp->z_mapcnt > 0 && MANDMODE(zp->z_mode)) {
4863                 ZFS_EXIT(zfsvfs);
4864                 return (SET_ERROR(EAGAIN));
4865         }
4866         ZFS_EXIT(zfsvfs);
4867         return (fs_frlock(vp, cmd, bfp, flag, offset, flk_cbp, cr, ct));
4868 }
4869 
4870 /*
4871  * If we can't find a page in the cache, we will create a new page
4872  * and fill it with file data.  For efficiency, we may try to fill
4873  * multiple pages at once (klustering) to fill up the supplied page
4874  * list.  Note that the pages to be filled are held with an exclusive
4875  * lock to prevent access by other threads while they are being filled.
4876  */
4877 static int
4878 zfs_fillpage(vnode_t *vp, u_offset_t off, struct seg *seg,
4879     caddr_t addr, page_t *pl[], size_t plsz, enum seg_rw rw)
4880 {
4881         znode_t *zp = VTOZ(vp);
4882         page_t *pp, *cur_pp;
4883         objset_t *os = zp->z_zfsvfs->z_os;
4884         u_offset_t io_off, total;
4885         size_t io_len;
4886         int err;
4887 
4888         if (plsz == PAGESIZE || zp->z_blksz <= PAGESIZE) {
4889                 /*
4890                  * We only have a single page, don't bother klustering
4891                  */
4892                 io_off = off;
4893                 io_len = PAGESIZE;
4894                 pp = page_create_va(vp, io_off, io_len,
4895                     PG_EXCL | PG_WAIT, seg, addr);
4896         } else {
4897                 /*
4898                  * Try to find enough pages to fill the page list
4899                  */
4900                 pp = pvn_read_kluster(vp, off, seg, addr, &io_off,
4901                     &io_len, off, plsz, 0);
4902         }
4903         if (pp == NULL) {
4904                 /*
4905                  * The page already exists, nothing to do here.
4906                  */
4907                 *pl = NULL;
4908                 return (0);
4909         }
4910 
4911         /*
4912          * Fill the pages in the kluster.
4913          */
4914         cur_pp = pp;
4915         for (total = io_off + io_len; io_off < total; io_off += PAGESIZE) {
4916                 caddr_t va;
4917 
4918                 ASSERT3U(io_off, ==, cur_pp->p_offset);
4919                 va = zfs_map_page(cur_pp, S_WRITE);
4920                 err = dmu_read(os, zp->z_id, io_off, PAGESIZE, va,
4921                     DMU_READ_PREFETCH);
4922                 zfs_unmap_page(cur_pp, va);
4923                 if (err) {
4924                         /* On error, toss the entire kluster */
4925                         pvn_read_done(pp, B_ERROR);
4926                         /* convert checksum errors into IO errors */
4927                         if (err == ECKSUM)
4928                                 err = SET_ERROR(EIO);
4929                         return (err);
4930                 }
4931                 cur_pp = cur_pp->p_next;
4932         }
4933 
4934         /*
4935          * Fill in the page list array from the kluster starting
4936          * from the desired offset `off'.
4937          * NOTE: the page list will always be null terminated.
4938          */
4939         pvn_plist_init(pp, pl, plsz, off, io_len, rw);
4940         ASSERT(pl == NULL || (*pl)->p_offset == off);
4941 
4942         return (0);
4943 }
4944 
4945 /*
4946  * Return pointers to the pages for the file region [off, off + len]
4947  * in the pl array.  If plsz is greater than len, this function may
4948  * also return page pointers from after the specified region
4949  * (i.e. the region [off, off + plsz]).  These additional pages are
4950  * only returned if they are already in the cache, or were created as
4951  * part of a klustered read.
4952  *
4953  *      IN:     vp      - vnode of file to get data from.
4954  *              off     - position in file to get data from.
4955  *              len     - amount of data to retrieve.
4956  *              plsz    - length of provided page list.
4957  *              seg     - segment to obtain pages for.
4958  *              addr    - virtual address of fault.
4959  *              rw      - mode of created pages.
4960  *              cr      - credentials of caller.
4961  *              ct      - caller context.
4962  *
4963  *      OUT:    protp   - protection mode of created pages.
4964  *              pl      - list of pages created.
4965  *
4966  *      RETURN: 0 on success, error code on failure.
4967  *
4968  * Timestamps:
4969  *      vp - atime updated
4970  */
4971 /* ARGSUSED */
4972 static int
4973 zfs_getpage(vnode_t *vp, offset_t off, size_t len, uint_t *protp,
4974     page_t *pl[], size_t plsz, struct seg *seg, caddr_t addr,
4975     enum seg_rw rw, cred_t *cr, caller_context_t *ct)
4976 {
4977         znode_t         *zp = VTOZ(vp);
4978         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
4979         page_t          **pl0 = pl;
4980         int             err = 0;
4981 
4982         /* we do our own caching, faultahead is unnecessary */
4983         if (pl == NULL)
4984                 return (0);
4985         else if (len > plsz)
4986                 len = plsz;
4987         else
4988                 len = P2ROUNDUP(len, PAGESIZE);
4989         ASSERT(plsz >= len);
4990 
4991         ZFS_ENTER(zfsvfs);
4992         ZFS_VERIFY_ZP(zp);
4993 
4994         if (protp)
4995                 *protp = PROT_ALL;
4996 
4997         /*
4998          * Loop through the requested range [off, off + len) looking
4999          * for pages.  If we don't find a page, we will need to create
5000          * a new page and fill it with data from the file.
5001          */
5002         while (len > 0) {
5003                 if (*pl = page_lookup(vp, off, SE_SHARED))
5004                         *(pl+1) = NULL;
5005                 else if (err = zfs_fillpage(vp, off, seg, addr, pl, plsz, rw))
5006                         goto out;
5007                 while (*pl) {
5008                         ASSERT3U((*pl)->p_offset, ==, off);
5009                         off += PAGESIZE;
5010                         addr += PAGESIZE;
5011                         if (len > 0) {
5012                                 ASSERT3U(len, >=, PAGESIZE);
5013                                 len -= PAGESIZE;
5014                         }
5015                         ASSERT3U(plsz, >=, PAGESIZE);
5016                         plsz -= PAGESIZE;
5017                         pl++;
5018                 }
5019         }
5020 
5021         /*
5022          * Fill out the page array with any pages already in the cache.
5023          */
5024         while (plsz > 0 &&
5025             (*pl++ = page_lookup_nowait(vp, off, SE_SHARED))) {
5026                         off += PAGESIZE;
5027                         plsz -= PAGESIZE;
5028         }
5029 out:
5030         if (err) {
5031                 /*
5032                  * Release any pages we have previously locked.
5033                  */
5034                 while (pl > pl0)
5035                         page_unlock(*--pl);
5036         } else {
5037                 ZFS_ACCESSTIME_STAMP(zfsvfs, zp);
5038         }
5039 
5040         *pl = NULL;
5041 
5042         ZFS_EXIT(zfsvfs);
5043         return (err);
5044 }
5045 
5046 /*
5047  * Request a memory map for a section of a file.  This code interacts
5048  * with common code and the VM system as follows:
5049  *
5050  * - common code calls mmap(), which ends up in smmap_common()
5051  * - this calls VOP_MAP(), which takes you into (say) zfs
5052  * - zfs_map() calls as_map(), passing segvn_create() as the callback
5053  * - segvn_create() creates the new segment and calls VOP_ADDMAP()
5054  * - zfs_addmap() updates z_mapcnt
5055  */
5056 /*ARGSUSED*/
5057 static int
5058 zfs_map(vnode_t *vp, offset_t off, struct as *as, caddr_t *addrp,
5059     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
5060     caller_context_t *ct)
5061 {
5062         znode_t *zp = VTOZ(vp);
5063         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5064         segvn_crargs_t  vn_a;
5065         int             error;
5066 
5067         ZFS_ENTER(zfsvfs);
5068         ZFS_VERIFY_ZP(zp);
5069 
5070         /*
5071          * Note: ZFS_READONLY is handled in zfs_zaccess_common.
5072          */
5073 
5074         if ((prot & PROT_WRITE) && (zp->z_pflags &
5075             (ZFS_IMMUTABLE | ZFS_APPENDONLY))) {
5076                 ZFS_EXIT(zfsvfs);
5077                 return (SET_ERROR(EPERM));
5078         }
5079 
5080         if ((prot & (PROT_READ | PROT_EXEC)) &&
5081             (zp->z_pflags & ZFS_AV_QUARANTINED)) {
5082                 ZFS_EXIT(zfsvfs);
5083                 return (SET_ERROR(EACCES));
5084         }
5085 
5086         if (vp->v_flag & VNOMAP) {
5087                 ZFS_EXIT(zfsvfs);
5088                 return (SET_ERROR(ENOSYS));
5089         }
5090 
5091         if (off < 0 || len > MAXOFFSET_T - off) {
5092                 ZFS_EXIT(zfsvfs);
5093                 return (SET_ERROR(ENXIO));
5094         }
5095 
5096         if (vp->v_type != VREG) {
5097                 ZFS_EXIT(zfsvfs);
5098                 return (SET_ERROR(ENODEV));
5099         }
5100 
5101         /*
5102          * If file is locked, disallow mapping.
5103          */
5104         if (MANDMODE(zp->z_mode) && vn_has_flocks(vp)) {
5105                 ZFS_EXIT(zfsvfs);
5106                 return (SET_ERROR(EAGAIN));
5107         }
5108 
5109         as_rangelock(as);
5110         error = choose_addr(as, addrp, len, off, ADDR_VACALIGN, flags);
5111         if (error != 0) {
5112                 as_rangeunlock(as);
5113                 ZFS_EXIT(zfsvfs);
5114                 return (error);
5115         }
5116 
5117         vn_a.vp = vp;
5118         vn_a.offset = (u_offset_t)off;
5119         vn_a.type = flags & MAP_TYPE;
5120         vn_a.prot = prot;
5121         vn_a.maxprot = maxprot;
5122         vn_a.cred = cr;
5123         vn_a.amp = NULL;
5124         vn_a.flags = flags & ~MAP_TYPE;
5125         vn_a.szc = 0;
5126         vn_a.lgrp_mem_policy_flags = 0;
5127 
5128         error = as_map(as, *addrp, len, segvn_create, &vn_a);
5129 
5130         as_rangeunlock(as);
5131         ZFS_EXIT(zfsvfs);
5132         return (error);
5133 }
5134 
5135 /* ARGSUSED */
5136 static int
5137 zfs_addmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
5138     size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cr,
5139     caller_context_t *ct)
5140 {
5141         uint64_t pages = btopr(len);
5142 
5143         atomic_add_64(&VTOZ(vp)->z_mapcnt, pages);
5144         return (0);
5145 }
5146 
5147 /*
5148  * The reason we push dirty pages as part of zfs_delmap() is so that we get a
5149  * more accurate mtime for the associated file.  Since we don't have a way of
5150  * detecting when the data was actually modified, we have to resort to
5151  * heuristics.  If an explicit msync() is done, then we mark the mtime when the
5152  * last page is pushed.  The problem occurs when the msync() call is omitted,
5153  * which by far the most common case:
5154  *
5155  *      open()
5156  *      mmap()
5157  *      <modify memory>
5158  *      munmap()
5159  *      close()
5160  *      <time lapse>
5161  *      putpage() via fsflush
5162  *
5163  * If we wait until fsflush to come along, we can have a modification time that
5164  * is some arbitrary point in the future.  In order to prevent this in the
5165  * common case, we flush pages whenever a (MAP_SHARED, PROT_WRITE) mapping is
5166  * torn down.
5167  */
5168 /* ARGSUSED */
5169 static int
5170 zfs_delmap(vnode_t *vp, offset_t off, struct as *as, caddr_t addr,
5171     size_t len, uint_t prot, uint_t maxprot, uint_t flags, cred_t *cr,
5172     caller_context_t *ct)
5173 {
5174         uint64_t pages = btopr(len);
5175 
5176         ASSERT3U(VTOZ(vp)->z_mapcnt, >=, pages);
5177         atomic_add_64(&VTOZ(vp)->z_mapcnt, -pages);
5178 
5179         if ((flags & MAP_SHARED) && (prot & PROT_WRITE) &&
5180             vn_has_cached_data(vp))
5181                 (void) VOP_PUTPAGE(vp, off, len, B_ASYNC, cr, ct);
5182 
5183         return (0);
5184 }
5185 
5186 /*
5187  * Free or allocate space in a file.  Currently, this function only
5188  * supports the `F_FREESP' command.  However, this command is somewhat
5189  * misnamed, as its functionality includes the ability to allocate as
5190  * well as free space.
5191  *
5192  *      IN:     vp      - vnode of file to free data in.
5193  *              cmd     - action to take (only F_FREESP supported).
5194  *              bfp     - section of file to free/alloc.
5195  *              flag    - current file open mode flags.
5196  *              offset  - current file offset.
5197  *              cr      - credentials of caller [UNUSED].
5198  *              ct      - caller context.
5199  *
5200  *      RETURN: 0 on success, error code on failure.
5201  *
5202  * Timestamps:
5203  *      vp - ctime|mtime updated
5204  */
5205 /* ARGSUSED */
5206 static int
5207 zfs_space(vnode_t *vp, int cmd, flock64_t *bfp, int flag,
5208     offset_t offset, cred_t *cr, caller_context_t *ct)
5209 {
5210         znode_t         *zp = VTOZ(vp);
5211         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
5212         uint64_t        off, len;
5213         int             error;
5214 
5215         ZFS_ENTER(zfsvfs);
5216         ZFS_VERIFY_ZP(zp);
5217 
5218         if (cmd != F_FREESP) {
5219                 ZFS_EXIT(zfsvfs);
5220                 return (SET_ERROR(EINVAL));
5221         }
5222 
5223         /*
5224          * In a case vp->v_vfsp != zp->z_zfsvfs->z_vfs (e.g. snapshots) our
5225          * callers might not be able to detect properly that we are read-only,
5226          * so check it explicitly here.
5227          */
5228         if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
5229                 ZFS_EXIT(zfsvfs);
5230                 return (SET_ERROR(EROFS));
5231         }
5232 
5233         if (error = convoff(vp, bfp, 0, offset)) {
5234                 ZFS_EXIT(zfsvfs);
5235                 return (error);
5236         }
5237 
5238         if (bfp->l_len < 0) {
5239                 ZFS_EXIT(zfsvfs);
5240                 return (SET_ERROR(EINVAL));
5241         }
5242 
5243         off = bfp->l_start;
5244         len = bfp->l_len; /* 0 means from off to end of file */
5245 
5246         error = zfs_freesp(zp, off, len, flag, TRUE);
5247 
5248         if (error == 0 && off == 0 && len == 0)
5249                 vnevent_truncate(ZTOV(zp), ct);
5250 
5251         ZFS_EXIT(zfsvfs);
5252         return (error);
5253 }
5254 
5255 /*ARGSUSED*/
5256 static int
5257 zfs_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
5258 {
5259         znode_t         *zp = VTOZ(vp);
5260         zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
5261         uint32_t        gen;
5262         uint64_t        gen64;
5263         uint64_t        object = zp->z_id;
5264         zfid_short_t    *zfid;
5265         int             size, i, error;
5266 
5267         ZFS_ENTER(zfsvfs);
5268         ZFS_VERIFY_ZP(zp);
5269 
5270         if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs),
5271             &gen64, sizeof (uint64_t))) != 0) {
5272                 ZFS_EXIT(zfsvfs);
5273                 return (error);
5274         }
5275 
5276         gen = (uint32_t)gen64;
5277 
5278         size = (zfsvfs->z_parent != zfsvfs) ? LONG_FID_LEN : SHORT_FID_LEN;
5279         if (fidp->fid_len < size) {
5280                 fidp->fid_len = size;
5281                 ZFS_EXIT(zfsvfs);
5282                 return (SET_ERROR(ENOSPC));
5283         }
5284 
5285         zfid = (zfid_short_t *)fidp;
5286 
5287         zfid->zf_len = size;
5288 
5289         for (i = 0; i < sizeof (zfid->zf_object); i++)
5290                 zfid->zf_object[i] = (uint8_t)(object >> (8 * i));
5291 
5292         /* Must have a non-zero generation number to distinguish from .zfs */
5293         if (gen == 0)
5294                 gen = 1;
5295         for (i = 0; i < sizeof (zfid->zf_gen); i++)
5296                 zfid->zf_gen[i] = (uint8_t)(gen >> (8 * i));
5297 
5298         if (size == LONG_FID_LEN) {
5299                 uint64_t        objsetid = dmu_objset_id(zfsvfs->z_os);
5300                 zfid_long_t     *zlfid;
5301 
5302                 zlfid = (zfid_long_t *)fidp;
5303 
5304                 for (i = 0; i < sizeof (zlfid->zf_setid); i++)
5305                         zlfid->zf_setid[i] = (uint8_t)(objsetid >> (8 * i));
5306 
5307                 /* XXX - this should be the generation number for the objset */
5308                 for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
5309                         zlfid->zf_setgen[i] = 0;
5310         }
5311 
5312         ZFS_EXIT(zfsvfs);
5313         return (0);
5314 }
5315 
5316 static int
5317 zfs_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
5318     caller_context_t *ct)
5319 {
5320         znode_t         *zp, *xzp;
5321         zfsvfs_t        *zfsvfs;
5322         zfs_dirlock_t   *dl;
5323         int             error;
5324 
5325         switch (cmd) {
5326         case _PC_LINK_MAX:
5327                 *valp = ULONG_MAX;
5328                 return (0);
5329 
5330         case _PC_FILESIZEBITS:
5331                 *valp = 64;
5332                 return (0);
5333 
5334         case _PC_XATTR_EXISTS:
5335                 zp = VTOZ(vp);
5336                 zfsvfs = zp->z_zfsvfs;
5337                 ZFS_ENTER(zfsvfs);
5338                 ZFS_VERIFY_ZP(zp);
5339                 *valp = 0;
5340                 error = zfs_dirent_lock(&dl, zp, "", &xzp,
5341                     ZXATTR | ZEXISTS | ZSHARED, NULL, NULL);
5342                 if (error == 0) {
5343                         zfs_dirent_unlock(dl);
5344                         if (!zfs_dirempty(xzp))
5345                                 *valp = 1;
5346                         VN_RELE(ZTOV(xzp));
5347                 } else if (error == ENOENT) {
5348                         /*
5349                          * If there aren't extended attributes, it's the
5350                          * same as having zero of them.
5351                          */
5352                         error = 0;
5353                 }
5354                 ZFS_EXIT(zfsvfs);
5355                 return (error);
5356 
5357         case _PC_SATTR_ENABLED:
5358         case _PC_SATTR_EXISTS:
5359                 *valp = vfs_has_feature(vp->v_vfsp, VFSFT_SYSATTR_VIEWS) &&
5360                     (vp->v_type == VREG || vp->v_type == VDIR);
5361                 return (0);
5362 
5363         case _PC_ACCESS_FILTERING:
5364                 *valp = vfs_has_feature(vp->v_vfsp, VFSFT_ACCESS_FILTER) &&
5365                     vp->v_type == VDIR;
5366                 return (0);
5367 
5368         case _PC_ACL_ENABLED:
5369                 *valp = _ACL_ACE_ENABLED;
5370                 return (0);
5371 
5372         case _PC_MIN_HOLE_SIZE:
5373                 *valp = (ulong_t)SPA_MINBLOCKSIZE;
5374                 return (0);
5375 
5376         case _PC_TIMESTAMP_RESOLUTION:
5377                 /* nanosecond timestamp resolution */
5378                 *valp = 1L;
5379                 return (0);
5380 
5381         default:
5382                 return (fs_pathconf(vp, cmd, valp, cr, ct));
5383         }
5384 }
5385 
5386 /*ARGSUSED*/
5387 static int
5388 zfs_getsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
5389     caller_context_t *ct)
5390 {
5391         znode_t *zp = VTOZ(vp);
5392         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5393         int error;
5394         boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
5395 
5396         ZFS_ENTER(zfsvfs);
5397         ZFS_VERIFY_ZP(zp);
5398         error = zfs_getacl(zp, vsecp, skipaclchk, cr);
5399         ZFS_EXIT(zfsvfs);
5400 
5401         return (error);
5402 }
5403 
5404 /*ARGSUSED*/
5405 static int
5406 zfs_setsecattr(vnode_t *vp, vsecattr_t *vsecp, int flag, cred_t *cr,
5407     caller_context_t *ct)
5408 {
5409         znode_t *zp = VTOZ(vp);
5410         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5411         int error;
5412         boolean_t skipaclchk = (flag & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
5413         zilog_t *zilog = zfsvfs->z_log;
5414 
5415         ZFS_ENTER(zfsvfs);
5416         ZFS_VERIFY_ZP(zp);
5417 
5418         error = zfs_setacl(zp, vsecp, skipaclchk, cr);
5419 
5420         if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
5421                 zil_commit(zilog, 0);
5422 
5423         ZFS_EXIT(zfsvfs);
5424         return (error);
5425 }
5426 
5427 /*
5428  * The smallest read we may consider to loan out an arcbuf.
5429  * This must be a power of 2.
5430  */
5431 int zcr_blksz_min = (1 << 10);    /* 1K */
5432 /*
5433  * If set to less than the file block size, allow loaning out of an
5434  * arcbuf for a partial block read.  This must be a power of 2.
5435  */
5436 int zcr_blksz_max = (1 << 17);    /* 128K */
5437 
5438 /*ARGSUSED*/
5439 static int
5440 zfs_reqzcbuf(vnode_t *vp, enum uio_rw ioflag, xuio_t *xuio, cred_t *cr,
5441     caller_context_t *ct)
5442 {
5443         znode_t *zp = VTOZ(vp);
5444         zfsvfs_t *zfsvfs = zp->z_zfsvfs;
5445         int max_blksz = zfsvfs->z_max_blksz;
5446         uio_t *uio = &xuio->xu_uio;
5447         ssize_t size = uio->uio_resid;
5448         offset_t offset = uio->uio_loffset;
5449         int blksz;
5450         int fullblk, i;
5451         arc_buf_t *abuf;
5452         ssize_t maxsize;
5453         int preamble, postamble;
5454 
5455         if (xuio->xu_type != UIOTYPE_ZEROCOPY)
5456                 return (SET_ERROR(EINVAL));
5457 
5458         ZFS_ENTER(zfsvfs);
5459         ZFS_VERIFY_ZP(zp);
5460         switch (ioflag) {
5461         case UIO_WRITE:
5462                 /*
5463                  * Loan out an arc_buf for write if write size is bigger than
5464                  * max_blksz, and the file's block size is also max_blksz.
5465                  */
5466                 blksz = max_blksz;
5467                 if (size < blksz || zp->z_blksz != blksz) {
5468                         ZFS_EXIT(zfsvfs);
5469                         return (SET_ERROR(EINVAL));
5470                 }
5471                 /*
5472                  * Caller requests buffers for write before knowing where the
5473                  * write offset might be (e.g. NFS TCP write).
5474                  */
5475                 if (offset == -1) {
5476                         preamble = 0;
5477                 } else {
5478                         preamble = P2PHASE(offset, blksz);
5479                         if (preamble) {
5480                                 preamble = blksz - preamble;
5481                                 size -= preamble;
5482                         }
5483                 }
5484 
5485                 postamble = P2PHASE(size, blksz);
5486                 size -= postamble;
5487 
5488                 fullblk = size / blksz;
5489                 (void) dmu_xuio_init(xuio,
5490                     (preamble != 0) + fullblk + (postamble != 0));
5491                 DTRACE_PROBE3(zfs_reqzcbuf_align, int, preamble,
5492                     int, postamble, int,
5493                     (preamble != 0) + fullblk + (postamble != 0));
5494 
5495                 /*
5496                  * Have to fix iov base/len for partial buffers.  They
5497                  * currently represent full arc_buf's.
5498                  */
5499                 if (preamble) {
5500                         /* data begins in the middle of the arc_buf */
5501                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5502                             blksz);
5503                         ASSERT(abuf);
5504                         (void) dmu_xuio_add(xuio, abuf,
5505                             blksz - preamble, preamble);
5506                 }
5507 
5508                 for (i = 0; i < fullblk; i++) {
5509                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5510                             blksz);
5511                         ASSERT(abuf);
5512                         (void) dmu_xuio_add(xuio, abuf, 0, blksz);
5513                 }
5514 
5515                 if (postamble) {
5516                         /* data ends in the middle of the arc_buf */
5517                         abuf = dmu_request_arcbuf(sa_get_db(zp->z_sa_hdl),
5518                             blksz);
5519                         ASSERT(abuf);
5520                         (void) dmu_xuio_add(xuio, abuf, 0, postamble);
5521                 }
5522                 break;
5523         case UIO_READ:
5524                 /*
5525                  * Loan out an arc_buf for read if the read size is larger than
5526                  * the current file block size.  Block alignment is not
5527                  * considered.  Partial arc_buf will be loaned out for read.
5528                  */
5529                 blksz = zp->z_blksz;
5530                 if (blksz < zcr_blksz_min)
5531                         blksz = zcr_blksz_min;
5532                 if (blksz > zcr_blksz_max)
5533                         blksz = zcr_blksz_max;
5534                 /* avoid potential complexity of dealing with it */
5535                 if (blksz > max_blksz) {
5536                         ZFS_EXIT(zfsvfs);
5537                         return (SET_ERROR(EINVAL));
5538                 }
5539 
5540                 maxsize = zp->z_size - uio->uio_loffset;
5541                 if (size > maxsize)
5542                         size = maxsize;
5543 
5544                 if (size < blksz || vn_has_cached_data(vp)) {
5545                         ZFS_EXIT(zfsvfs);
5546                         return (SET_ERROR(EINVAL));
5547                 }
5548                 break;
5549         default:
5550                 ZFS_EXIT(zfsvfs);
5551                 return (SET_ERROR(EINVAL));
5552         }
5553 
5554         uio->uio_extflg = UIO_XUIO;
5555         XUIO_XUZC_RW(xuio) = ioflag;
5556         ZFS_EXIT(zfsvfs);
5557         return (0);
5558 }
5559 
5560 /*ARGSUSED*/
5561 static int
5562 zfs_retzcbuf(vnode_t *vp, xuio_t *xuio, cred_t *cr, caller_context_t *ct)
5563 {
5564         int i;
5565         arc_buf_t *abuf;
5566         int ioflag = XUIO_XUZC_RW(xuio);
5567 
5568         ASSERT(xuio->xu_type == UIOTYPE_ZEROCOPY);
5569 
5570         i = dmu_xuio_cnt(xuio);
5571         while (i-- > 0) {
5572                 abuf = dmu_xuio_arcbuf(xuio, i);
5573                 /*
5574                  * if abuf == NULL, it must be a write buffer
5575                  * that has been returned in zfs_write().
5576                  */
5577                 if (abuf)
5578                         dmu_return_arcbuf(abuf);
5579                 ASSERT(abuf || ioflag == UIO_WRITE);
5580         }
5581 
5582         dmu_xuio_fini(xuio);
5583         return (0);
5584 }
5585 
5586 /*
5587  * Predeclare these here so that the compiler assumes that
5588  * this is an "old style" function declaration that does
5589  * not include arguments => we won't get type mismatch errors
5590  * in the initializations that follow.
5591  */
5592 static int zfs_inval();
5593 static int zfs_isdir();
5594 
5595 static int
5596 zfs_inval()
5597 {
5598         return (SET_ERROR(EINVAL));
5599 }
5600 
5601 static int
5602 zfs_isdir()
5603 {
5604         return (SET_ERROR(EISDIR));
5605 }
5606 /*
5607  * Directory vnode operations template
5608  */
5609 vnodeops_t *zfs_dvnodeops;
5610 const fs_operation_def_t zfs_dvnodeops_template[] = {
5611         VOPNAME_OPEN,           { .vop_open = zfs_open },
5612         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5613         VOPNAME_READ,           { .error = zfs_isdir },
5614         VOPNAME_WRITE,          { .error = zfs_isdir },
5615         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5616         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5617         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5618         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5619         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5620         VOPNAME_CREATE,         { .vop_create = zfs_create },
5621         VOPNAME_REMOVE,         { .vop_remove = zfs_remove },
5622         VOPNAME_LINK,           { .vop_link = zfs_link },
5623         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5624         VOPNAME_MKDIR,          { .vop_mkdir = zfs_mkdir },
5625         VOPNAME_RMDIR,          { .vop_rmdir = zfs_rmdir },
5626         VOPNAME_READDIR,        { .vop_readdir = zfs_readdir },
5627         VOPNAME_SYMLINK,        { .vop_symlink = zfs_symlink },
5628         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5629         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5630         VOPNAME_FID,            { .vop_fid = zfs_fid },
5631         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5632         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5633         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5634         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5635         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5636         NULL,                   NULL
5637 };
5638 
5639 /*
5640  * Regular file vnode operations template
5641  */
5642 vnodeops_t *zfs_fvnodeops;
5643 const fs_operation_def_t zfs_fvnodeops_template[] = {
5644         VOPNAME_OPEN,           { .vop_open = zfs_open },
5645         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5646         VOPNAME_READ,           { .vop_read = zfs_read },
5647         VOPNAME_WRITE,          { .vop_write = zfs_write },
5648         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5649         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5650         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5651         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5652         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5653         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5654         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5655         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5656         VOPNAME_FID,            { .vop_fid = zfs_fid },
5657         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5658         VOPNAME_FRLOCK,         { .vop_frlock = zfs_frlock },
5659         VOPNAME_SPACE,          { .vop_space = zfs_space },
5660         VOPNAME_GETPAGE,        { .vop_getpage = zfs_getpage },
5661         VOPNAME_PUTPAGE,        { .vop_putpage = zfs_putpage },
5662         VOPNAME_MAP,            { .vop_map = zfs_map },
5663         VOPNAME_ADDMAP,         { .vop_addmap = zfs_addmap },
5664         VOPNAME_DELMAP,         { .vop_delmap = zfs_delmap },
5665         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5666         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5667         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5668         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5669         VOPNAME_REQZCBUF,       { .vop_reqzcbuf = zfs_reqzcbuf },
5670         VOPNAME_RETZCBUF,       { .vop_retzcbuf = zfs_retzcbuf },
5671         NULL,                   NULL
5672 };
5673 
5674 /*
5675  * Symbolic link vnode operations template
5676  */
5677 vnodeops_t *zfs_symvnodeops;
5678 const fs_operation_def_t zfs_symvnodeops_template[] = {
5679         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5680         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5681         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5682         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5683         VOPNAME_READLINK,       { .vop_readlink = zfs_readlink },
5684         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5685         VOPNAME_FID,            { .vop_fid = zfs_fid },
5686         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5687         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5688         NULL,                   NULL
5689 };
5690 
5691 /*
5692  * special share hidden files vnode operations template
5693  */
5694 vnodeops_t *zfs_sharevnodeops;
5695 const fs_operation_def_t zfs_sharevnodeops_template[] = {
5696         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5697         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5698         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5699         VOPNAME_FID,            { .vop_fid = zfs_fid },
5700         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5701         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5702         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5703         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5704         NULL,                   NULL
5705 };
5706 
5707 /*
5708  * Extended attribute directory vnode operations template
5709  *
5710  * This template is identical to the directory vnodes
5711  * operation template except for restricted operations:
5712  *      VOP_MKDIR()
5713  *      VOP_SYMLINK()
5714  *
5715  * Note that there are other restrictions embedded in:
5716  *      zfs_create()    - restrict type to VREG
5717  *      zfs_link()      - no links into/out of attribute space
5718  *      zfs_rename()    - no moves into/out of attribute space
5719  */
5720 vnodeops_t *zfs_xdvnodeops;
5721 const fs_operation_def_t zfs_xdvnodeops_template[] = {
5722         VOPNAME_OPEN,           { .vop_open = zfs_open },
5723         VOPNAME_CLOSE,          { .vop_close = zfs_close },
5724         VOPNAME_IOCTL,          { .vop_ioctl = zfs_ioctl },
5725         VOPNAME_GETATTR,        { .vop_getattr = zfs_getattr },
5726         VOPNAME_SETATTR,        { .vop_setattr = zfs_setattr },
5727         VOPNAME_ACCESS,         { .vop_access = zfs_access },
5728         VOPNAME_LOOKUP,         { .vop_lookup = zfs_lookup },
5729         VOPNAME_CREATE,         { .vop_create = zfs_create },
5730         VOPNAME_REMOVE,         { .vop_remove = zfs_remove },
5731         VOPNAME_LINK,           { .vop_link = zfs_link },
5732         VOPNAME_RENAME,         { .vop_rename = zfs_rename },
5733         VOPNAME_MKDIR,          { .error = zfs_inval },
5734         VOPNAME_RMDIR,          { .vop_rmdir = zfs_rmdir },
5735         VOPNAME_READDIR,        { .vop_readdir = zfs_readdir },
5736         VOPNAME_SYMLINK,        { .error = zfs_inval },
5737         VOPNAME_FSYNC,          { .vop_fsync = zfs_fsync },
5738         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5739         VOPNAME_FID,            { .vop_fid = zfs_fid },
5740         VOPNAME_SEEK,           { .vop_seek = zfs_seek },
5741         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5742         VOPNAME_GETSECATTR,     { .vop_getsecattr = zfs_getsecattr },
5743         VOPNAME_SETSECATTR,     { .vop_setsecattr = zfs_setsecattr },
5744         VOPNAME_VNEVENT,        { .vop_vnevent = fs_vnevent_support },
5745         NULL,                   NULL
5746 };
5747 
5748 /*
5749  * Error vnode operations template
5750  */
5751 vnodeops_t *zfs_evnodeops;
5752 const fs_operation_def_t zfs_evnodeops_template[] = {
5753         VOPNAME_INACTIVE,       { .vop_inactive = zfs_inactive },
5754         VOPNAME_PATHCONF,       { .vop_pathconf = zfs_pathconf },
5755         NULL,                   NULL
5756 };